diff --git a/Neos.Cache/Classes/Backend/AbstractBackend.php b/Neos.Cache/Classes/Backend/AbstractBackend.php
index 05dab6c87b..99b4afbf99 100644
--- a/Neos.Cache/Classes/Backend/AbstractBackend.php
+++ b/Neos.Cache/Classes/Backend/AbstractBackend.php
@@ -57,21 +57,18 @@ abstract class AbstractBackend implements BackendInterface
     /**
      * Constructs this backend
      *
-     * @param EnvironmentConfiguration $environmentConfiguration
-     * @param array $options Configuration options - depends on the actual backend
+     * @param array<string,mixed> $options Configuration options - depends on the actual backend
      * @api
      */
-    public function __construct(?EnvironmentConfiguration $environmentConfiguration = null, array $options = [])
+    public function __construct(EnvironmentConfiguration $environmentConfiguration = null, array $options = [])
     {
         $this->environmentConfiguration = $environmentConfiguration;
 
-        if (is_array($options) || $options instanceof \Iterator) {
-            $this->setProperties($options);
-        }
+        $this->setProperties($options);
     }
 
     /**
-     * @param array $properties
+     * @param array<string,mixed> $properties
      * @param boolean $throwExceptionIfPropertyNotSettable
      * @return void
      * @throws \InvalidArgumentException
@@ -117,7 +114,7 @@ public function setCache(FrontendInterface $cache): void
     {
         $this->cache = $cache;
         $this->cacheIdentifier = $this->cache->getIdentifier();
-        $applicationIdentifier = $this->environmentConfiguration instanceof EnvironmentConfiguration ? $this->environmentConfiguration->getApplicationIdentifier() : '';
+        $applicationIdentifier = $this->environmentConfiguration->getApplicationIdentifier();
         $this->identifierPrefix = md5($applicationIdentifier) . ':' . $this->cacheIdentifier . ':';
     }
 
diff --git a/Neos.Cache/Classes/Backend/TransientMemoryBackend.php b/Neos.Cache/Classes/Backend/TransientMemoryBackend.php
index 1ea561187c..8bceea8ab8 100644
--- a/Neos.Cache/Classes/Backend/TransientMemoryBackend.php
+++ b/Neos.Cache/Classes/Backend/TransientMemoryBackend.php
@@ -22,8 +22,14 @@
  *
  * @api
  */
-class TransientMemoryBackend extends IndependentAbstractBackend implements TaggableBackendInterface
+class TransientMemoryBackend implements TaggableBackendInterface
 {
+    /**
+     * Reference to the cache frontend which uses this backend
+     * @var FrontendInterface
+     */
+    protected $cache;
+
     /**
      * @var array
      */
@@ -34,6 +40,12 @@ class TransientMemoryBackend extends IndependentAbstractBackend implements Tagga
      */
     protected $tagsAndEntries = [];
 
+    // todo there is no real contract it will just be invoked with the env configuration and options .. :(
+    public function __construct()
+    {
+
+    }
+
     /**
      * Saves data in the cache.
      *
@@ -175,4 +187,15 @@ public function flushByTags(array $tags): int
     public function collectGarbage(): void
     {
     }
+
+    public function setCache(FrontendInterface $cache): void
+    {
+        $this->cache = $cache;
+    }
+
+    public function getPrefixedIdentifier(string $entryIdentifier): string
+    {
+        $identifierPrefix = $this->cache->getIdentifier() . ':';
+        return $identifierPrefix . $entryIdentifier;
+    }
 }
diff --git a/Neos.Flow.Log/Classes/Backend/AbstractBackend.php b/Neos.Flow.Log/Classes/Backend/AbstractBackend.php
index 6279d6cd85..1e879d90db 100644
--- a/Neos.Flow.Log/Classes/Backend/AbstractBackend.php
+++ b/Neos.Flow.Log/Classes/Backend/AbstractBackend.php
@@ -42,7 +42,7 @@ abstract class AbstractBackend implements BackendInterface
      */
     public function __construct($options = [])
     {
-        if (is_array($options) || $options instanceof \ArrayAccess) {
+        if (is_iterable($options)) {
             foreach ($options as $optionKey => $optionValue) {
                 $methodName = 'set' . ucfirst($optionKey);
                 if (method_exists($this, $methodName)) {
diff --git a/Neos.Flow.Log/Classes/Backend/AnsiConsoleBackend.php b/Neos.Flow.Log/Classes/Backend/AnsiConsoleBackend.php
index 5749b5df81..30784f9aef 100644
--- a/Neos.Flow.Log/Classes/Backend/AnsiConsoleBackend.php
+++ b/Neos.Flow.Log/Classes/Backend/AnsiConsoleBackend.php
@@ -40,7 +40,7 @@ class AnsiConsoleBackend extends ConsoleBackend
     const END = "\033[0m";
 
     /**
-     * @var array
+     * @var array<string,string>
      */
     protected $tagFormats = [];
 
@@ -75,12 +75,7 @@ public function open(): void
     /**
      * Appends the given message along with the additional information into the log.
      *
-     * @param string $message
-     * @param int $severity
-     * @param array $additionalData
-     * @param string $packageKey
-     * @param string $className
-     * @param string $methodName
+     * @param array<mixed>|null $additionalData
      * @return void
      */
     public function append(string $message, int $severity = LOG_INFO, $additionalData = null, ?string $packageKey = null, ?string $className = null, ?string $methodName = null): void
@@ -118,7 +113,7 @@ protected function formatOutput($output)
                 } else {
                     return str_replace('|', $matches[3], $format);
                 }
-            }, $output);
+            }, $output) ?: '';
         } while ($lastOutput !== $output);
         return $output;
     }
@@ -126,7 +121,7 @@ protected function formatOutput($output)
     /**
      * @param boolean $disableAnsi
      */
-    public function setDisableAnsi($disableAnsi)
+    public function setDisableAnsi($disableAnsi): void
     {
         $this->disableAnsi = $disableAnsi;
     }
diff --git a/Neos.Flow.Log/Classes/Backend/ConsoleBackend.php b/Neos.Flow.Log/Classes/Backend/ConsoleBackend.php
index def5dd734e..1398b288c9 100644
--- a/Neos.Flow.Log/Classes/Backend/ConsoleBackend.php
+++ b/Neos.Flow.Log/Classes/Backend/ConsoleBackend.php
@@ -25,7 +25,7 @@ class ConsoleBackend extends AbstractBackend
 {
     /**
      * An array of severity labels, indexed by their integer constant
-     * @var array
+     * @var array<int,string>
      */
     protected $severityLabels;
 
@@ -61,10 +61,11 @@ public function open(): void
             LOG_DEBUG => 'DEBUG    ',
         ];
 
-        $this->streamHandle = fopen('php://' . $this->streamName, 'w');
-        if (!is_resource($this->streamHandle)) {
+        $streamHandle = fopen('php://' . $this->streamName, 'w');
+        if (!is_resource($streamHandle)) {
             throw new CouldNotOpenResourceException('Could not open stream "' . $this->streamName . '" for write access.', 1310986609);
         }
+        $this->streamHandle = $streamHandle;
     }
 
     /**
diff --git a/Neos.Flow.Log/Classes/Backend/FileBackend.php b/Neos.Flow.Log/Classes/Backend/FileBackend.php
index 67a3ac2aaf..7a19df4a97 100644
--- a/Neos.Flow.Log/Classes/Backend/FileBackend.php
+++ b/Neos.Flow.Log/Classes/Backend/FileBackend.php
@@ -27,7 +27,7 @@ class FileBackend extends AbstractBackend
 {
     /**
      * An array of severity labels, indexed by their integer constant
-     * @var array
+     * @var array<int,string>
      */
     protected $severityLabels;
 
diff --git a/Neos.Flow.Log/Classes/PlainTextFormatter.php b/Neos.Flow.Log/Classes/PlainTextFormatter.php
index 0a15efb126..5590dbbed2 100644
--- a/Neos.Flow.Log/Classes/PlainTextFormatter.php
+++ b/Neos.Flow.Log/Classes/PlainTextFormatter.php
@@ -22,10 +22,9 @@ public function __construct($variable)
     }
 
     /**
-     * @param $spaces
-     * @return string
+     * @return ?string
      */
-    public function format($spaces = 4)
+    public function format(int $spaces = 4)
     {
         return $this->renderVariableAsPlaintext($this->variable, $spaces);
     }
diff --git a/Neos.Flow.Log/Classes/Psr/Logger.php b/Neos.Flow.Log/Classes/Psr/Logger.php
index 6ebad73f56..c1a18be6f8 100644
--- a/Neos.Flow.Log/Classes/Psr/Logger.php
+++ b/Neos.Flow.Log/Classes/Psr/Logger.php
@@ -45,7 +45,7 @@ class Logger implements LoggerInterface
     /**
      * Constructs the PSR-3 Logger.
      *
-     * @param iterable $backends
+     * @param iterable<mixed> $backends
      */
     public function __construct(iterable $backends)
     {
@@ -61,7 +61,7 @@ public function __construct(iterable $backends)
     /**
      * @param mixed $level
      * @param string|\Stringable $message
-     * @param array $context
+     * @param array<string,mixed> $context
      * @api
      */
     public function log($level, string|\Stringable $message, array $context = []): void
@@ -80,8 +80,8 @@ public function log($level, string|\Stringable $message, array $context = []): v
     }
 
     /**
-     * @param array $context
-     * @return array list of packageKey, className and methodName either string or null
+     * @param array<string,mixed> $context
+     * @return array<int,string|null> list of packageKey, className and methodName either string or null
      */
     protected function extractLegacyDataFromContext(array $context): array
     {
@@ -93,8 +93,8 @@ protected function extractLegacyDataFromContext(array $context): array
     }
 
     /**
-     * @param array $context
-     * @return array
+     * @param array<string,mixed> $context
+     * @return array<string,mixed>
      */
     protected function removeLegacyDataFromContext(array $context): array
     {
diff --git a/Neos.Flow/Classes/Package/FlowPackageKey.php b/Neos.Flow/Classes/Package/FlowPackageKey.php
index 5e5a72ec6e..fe23b20851 100644
--- a/Neos.Flow/Classes/Package/FlowPackageKey.php
+++ b/Neos.Flow/Classes/Package/FlowPackageKey.php
@@ -37,7 +37,7 @@ private function __construct(
         }
     }
 
-    public static function fromString(string $value)
+    public static function fromString(string $value): self
     {
         return new self($value);
     }
@@ -63,6 +63,9 @@ public static function isPackageKeyValid(string $string): bool
      * case version of the composer name / namespace will be used, with backslashes replaced by dots.
      *
      * Else the composer name will be used with the slash replaced by a dot
+     *
+     * // @todo replace with ComposerManifest array shape / object from ComposerUtility
+     * @param array<string,mixed> $manifest
      */
     public static function deriveFromManifestOrPath(array $manifest, string $packagePath): self
     {
@@ -77,6 +80,7 @@ public static function deriveFromManifestOrPath(array $manifest, string $package
         $type = $manifest['type'] ?? null;
         if (isset($manifest['autoload']['psr-0']) && is_array($manifest['autoload']['psr-0'])) {
             $namespaces = array_keys($manifest['autoload']['psr-0']);
+            /** @var string $autoloadNamespace */
             $autoloadNamespace = reset($namespaces);
         }
         return self::derivePackageKeyInternal($composerName, $type, $packagePath, $autoloadNamespace);
@@ -110,7 +114,7 @@ private static function derivePackageKeyInternal(string $composerName, ?string $
         }
 
         $packageKey = trim($packageKey, '.');
-        $packageKey = preg_replace('/[^A-Za-z0-9.]/', '', $packageKey);
+        $packageKey = preg_replace('/[^A-Za-z0-9.]/', '', $packageKey) ?: '';
 
         return new self($packageKey);
     }
diff --git a/Neos.Flow/Classes/Package/GenericPackage.php b/Neos.Flow/Classes/Package/GenericPackage.php
index 20d63c4a5d..2b72702659 100644
--- a/Neos.Flow/Classes/Package/GenericPackage.php
+++ b/Neos.Flow/Classes/Package/GenericPackage.php
@@ -17,6 +17,12 @@
 
 /**
  * The generic base package that represents third party packages
+ *
+ * @phpstan-type AutoloadConfiguration array{
+ *     namespace: string,
+ *     classPath: string,
+ *     mappingType: string,
+ * }
  */
 class GenericPackage implements PackageInterface, PackageKeyAwareInterface
 {
@@ -54,12 +60,12 @@ class GenericPackage implements PackageInterface, PackageKeyAwareInterface
     protected $autoloadTypes;
 
     /**
-     * @var array
+     * @var array<string,AutoloadConfiguration>
      */
     protected $autoloadConfiguration;
 
     /**
-     * @var array
+     * @var array<int,AutoloadConfiguration>
      */
     protected $flattenedAutoloadConfiguration;
 
@@ -69,7 +75,7 @@ class GenericPackage implements PackageInterface, PackageKeyAwareInterface
      * @param string $packageKey Key of this package
      * @param string $composerName
      * @param string $packagePath Absolute path to the location of the package's composer manifest
-     * @param array $autoloadConfiguration
+     * @param array<string,AutoloadConfiguration> $autoloadConfiguration
      */
     public function __construct($packageKey, $composerName, $packagePath, array $autoloadConfiguration = [])
     {
@@ -82,7 +88,7 @@ public function __construct($packageKey, $composerName, $packagePath, array $aut
     /**
      * Returns the array of filenames of the class files
      *
-     * @return iterable A Generator for class names (key) and their filename, including the absolute path.
+     * @return iterable<string,string> A Generator for class names (key) and their filename, including the absolute path.
      */
     public function getClassFiles()
     {
@@ -121,7 +127,7 @@ public function getComposerName()
     /**
      * Returns array of all declared autoload namespaces contained in this package
      *
-     * @return array
+     * @return array<string>
      * @api
      */
     public function getNamespaces()
@@ -157,7 +163,7 @@ public function getPackagePath()
     }
 
     /**
-     * @return array
+     * @return array<string>
      */
     public function getAutoloadPaths()
     {
@@ -169,9 +175,9 @@ public function getAutoloadPaths()
     /**
      * Get the autoload configuration for this package. Any valid composer "autoload" configuration.
      *
-     * @return array
+     * @return array<string,AutoloadConfiguration>
      */
-    public function getAutoloadConfiguration()
+    public function getAutoloadConfiguration(): array
     {
         return $this->autoloadConfiguration;
     }
@@ -179,7 +185,7 @@ public function getAutoloadConfiguration()
     /**
      * Get a flattened array of autoload configurations that have a predictable pattern (PSR-0, PSR-4)
      *
-     * @return array Keys: "namespace", "classPath", "mappingType"
+     * @return array<int,AutoloadConfiguration>
      */
     public function getFlattenedAutoloadConfiguration()
     {
diff --git a/Neos.Flow/Classes/Package/Package.php b/Neos.Flow/Classes/Package/Package.php
index 45a4b47c30..4245509a17 100644
--- a/Neos.Flow/Classes/Package/Package.php
+++ b/Neos.Flow/Classes/Package/Package.php
@@ -42,8 +42,12 @@ public function getFunctionalTestsClassFiles()
         $namespaces = $this->getNamespaces();
         if (is_dir($this->packagePath . self::DIRECTORY_TESTS_FUNCTIONAL)) {
             // TODO REFACTOR replace with usage of "autoload-dev"
+            $namespace = reset($namespaces);
+            if (!$namespace) {
+                throw new \Exception('Missing namespace', 1744144110);
+            }
             $namespacePrefix = str_replace('/', '\\', Files::concatenatePaths([
-                reset($namespaces),
+                $namespace,
                 '\\Tests\\Functional\\'
             ]));
             foreach ($this->getClassesInNormalizedAutoloadPath($this->packagePath . FlowPackageInterface::DIRECTORY_TESTS_FUNCTIONAL, $namespacePrefix) as $className => $classPath) {
diff --git a/Neos.Flow/Classes/Package/PackageFactory.php b/Neos.Flow/Classes/Package/PackageFactory.php
index 8f9632e175..d67f720f70 100644
--- a/Neos.Flow/Classes/Package/PackageFactory.php
+++ b/Neos.Flow/Classes/Package/PackageFactory.php
@@ -27,7 +27,7 @@ class PackageFactory
      * @param string $packagePath path to package, relative to base path
      * @param FlowPackageKey $packageKey key / name of the package
      * @param string $composerName
-     * @param array $autoloadConfiguration Autoload configuration as defined in composer.json
+     * @param array<mixed> $autoloadConfiguration Autoload configuration as defined in composer.json
      * @param array{className: class-string<PackageInterface>, pathAndFilename: string}|null $packageClassInformation
      * @return PackageInterface&PackageKeyAwareInterface
      * @throws Exception\CorruptPackageException
@@ -49,9 +49,6 @@ public function create(string $packagesBasePath, string $packagePath, FlowPackag
 
         /** dynamic construction {@see GenericPackage::__construct} */
         $package = new $packageClassName($packageKey->value, $composerName, $absolutePackagePath, $autoloadConfiguration);
-        if (!$package instanceof PackageInterface) {
-            throw new Exception\CorruptPackageException(sprintf('The package class of package "%s" does not implement \Neos\Flow\Package\PackageInterface. Check the file "%s".', $packageKey->value, $packageClassInformation['pathAndFilename']), 1427193370);
-        }
         if (!$package instanceof PackageKeyAwareInterface) {
             throw new Exception\CorruptPackageException(sprintf('The package class of package "%s" does not implement \Neos\Flow\Package\PackageKeyAwareInterface. Check the file "%s".', $packageKey->value, $packageClassInformation['pathAndFilename']), 1711665156);
         }
@@ -100,8 +97,11 @@ public function detectFlowPackageFilePath(FlowPackageKey $packageKey, $absoluteP
         $absolutePackageClassPath = Files::concatenatePaths([$absolutePackagePath, $packageClassPathAndFilename]);
 
         $packageClassContents = file_get_contents($absolutePackageClassPath);
+        if (!$packageClassContents) {
+            throw new \Exception('Could not read package class file', 1744142431);
+        }
         $packageClassName = (new PhpAnalyzer($packageClassContents))->extractFullyQualifiedClassName();
-        if ($packageClassName === null) {
+        if ($packageClassName === null || !is_subclass_of($packageClassName, PackageInterface::class)) {
             throw new Exception\CorruptPackageException(sprintf('The package "%s" does not contain a valid package class. Check if the file "%s" really contains a class.', $packageKey->value, $packageClassPathAndFilename), 1327587091);
         }
 
diff --git a/Neos.Flow/Classes/Package/PackageInterface.php b/Neos.Flow/Classes/Package/PackageInterface.php
index b8ce3e2efd..d08d764258 100644
--- a/Neos.Flow/Classes/Package/PackageInterface.php
+++ b/Neos.Flow/Classes/Package/PackageInterface.php
@@ -25,7 +25,7 @@ interface PackageInterface
     /**
      * Returns the array of filenames of the class files
      *
-     * @return iterable An array or yields the class names (key) and their filename, including the relative path to the package's directory
+     * @return iterable<class-string,string> An array or yields the class names (key) and their filename, including the relative path to the package's directory
      * @api
      */
     public function getClassFiles();
@@ -41,7 +41,7 @@ public function getComposerName();
     /**
      * Returns an array of all namespaces declared for this package.
      *
-     * @return array
+     * @return array<string>
      * @api
      */
     public function getNamespaces();
diff --git a/Neos.Flow/Classes/Package/PackageManager.php b/Neos.Flow/Classes/Package/PackageManager.php
index d2b0522118..fdea0ef576 100644
--- a/Neos.Flow/Classes/Package/PackageManager.php
+++ b/Neos.Flow/Classes/Package/PackageManager.php
@@ -27,6 +27,13 @@
 /**
  * The default Flow Package Manager
  *
+ * @phpstan-type ComposerManifest array{
+ *     require?: array<string>,
+ *     extra?: array{neos?: array{loading-order?: array{after?: mixed}}},
+ *     autoload?: array<string,array<string,string>>,
+ *     name: string,
+ * }
+ *
  * @api
  * @Flow\Scope("singleton")
  */
@@ -60,7 +67,7 @@ class PackageManager
     /**
      * Array of available packages, indexed by package key (case sensitive)
      *
-     * @var array
+     * @var array<string,PackageInterface&PackageKeyAwareInterface>
      */
     protected $packages = [];
 
@@ -74,7 +81,7 @@ class PackageManager
     /**
      * A map between ComposerName and PackageKey, only available when scanAvailablePackages is run
      *
-     * @var array
+     * @var array<string,string>
      */
     protected $composerNameToPackageKeyMap = [];
 
@@ -93,12 +100,12 @@ class PackageManager
     /**
      * Package states configuration as stored in the PackageStates.php file
      *
-     * @var array
+     * @var array<mixed>
      */
     protected $packageStatesConfiguration = [];
 
     /**
-     * @var array
+     * @var array<mixed>
      */
     protected $settings;
 
@@ -111,7 +118,7 @@ class PackageManager
      * Inject settings into the package manager. Has to be called explicitly on object initialization as
      * the package manager subpackage is excluded from proxy class building.
      *
-     * @param array $settings
+     * @param array<string,mixed> $settings
      * @return void
      */
     public function injectSettings(array $settings): void
@@ -145,8 +152,6 @@ public function initialize(Bootstrap $bootstrap): void
         $this->bootstrap = $bootstrap;
         $this->packageStatesConfiguration = $this->getCurrentPackageStates();
         $this->registerPackagesFromConfiguration($this->packageStatesConfiguration);
-        /** @var PackageInterface $package */
-
         foreach ($this->packages as $package) {
             if ($package instanceof FlowPackageInterface) {
                 $this->flowPackages[$package->getPackageKey()] = $package;
@@ -197,11 +202,11 @@ public function getPackagesBasePath(): string
      * Returns a PackageInterface object for the specified package.
      *
      * @param string $packageKey
-     * @return PackageInterface The requested package object
+     * @return PackageInterface&PackageKeyAwareInterface The requested package object
      * @throws Exception\UnknownPackageException if the specified package is not known
      * @api
      */
-    public function getPackage($packageKey): PackageInterface
+    public function getPackage($packageKey): PackageInterface&PackageKeyAwareInterface
     {
         if (!$this->isPackageAvailable($packageKey)) {
             throw new Exception\UnknownPackageException('Package "' . $packageKey . '" is not available. Please check if the package exists and that the package key is correct (package keys are case sensitive).', 1166546734);
@@ -214,7 +219,7 @@ public function getPackage($packageKey): PackageInterface
      * Returns an array of PackageInterface objects of all available packages.
      * A package is available, if the package directory contains valid meta information.
      *
-     * @return array<PackageInterface>
+     * @return array<PackageInterface&PackageKeyAwareInterface>
      * @api
      */
     public function getAvailablePackages(): array
@@ -229,7 +234,7 @@ public function getAvailablePackages(): array
      * @param string $packageState defaults to available
      * @param string $packageType
      *
-     * @return array<PackageInterface>
+     * @return array<PackageInterface&PackageKeyAwareInterface>
      * @throws Exception\InvalidPackageStateException
      * @api
      */
@@ -256,9 +261,9 @@ public function getFilteredPackages($packageState = 'available', $packageType =
      * Returns an array of PackageInterface objects in the given array of packages
      * that are of the specified package type.
      *
-     * @param array $packages Array of PackageInterface objects to be filtered
+     * @param array<PackageInterface&PackageKeyAwareInterface> $packages Array of PackageInterface objects to be filtered
      * @param string $packageType Filter out anything that's not of this packageType
-     * @return array<PackageInterface>
+     * @return array<PackageInterface&PackageKeyAwareInterface>
      */
     protected function filterPackagesByType($packages, $packageType): array
     {
@@ -276,7 +281,7 @@ protected function filterPackagesByType($packages, $packageType): array
      * Create a package, given the package key
      *
      * @param string $packageKey The package key of the new package
-     * @param array $manifest A composer manifest as associative array.
+     * @param array<string,mixed> $manifest A composer manifest as associative array.
      * @param string $packagesPath If specified, the package will be created in this path, otherwise the default "Application" directory is used
      * @return PackageInterface The newly created package
      *
@@ -371,7 +376,7 @@ public function createPackage($packageKey, array $manifest = [], $packagesPath =
     /**
      * Rescans available packages, order and write a new PackageStates file.
      *
-     * @return array The found and sorted package states.
+     * @return array<mixed> The found and sorted package states.
      * @throws Exception
      * @throws InvalidConfigurationException
      * @throws FilesException
@@ -389,7 +394,7 @@ public function rescanPackages(): array
      * initialises a package scan if the file was not found or the configuration format
      * was not current.
      *
-     * @return array
+     * @return array<mixed>
      * @throws Exception
      * @throws InvalidConfigurationException
      * @throws FilesException
@@ -417,7 +422,7 @@ protected function getCurrentPackageStates(): array
     /**
      * Load the current package states
      *
-     * @return array
+     * @return array<mixed>
      */
     protected function loadPackageStates(): array
     {
@@ -428,7 +433,7 @@ protected function loadPackageStates(): array
      * Scans all directories in the packages directories for available packages.
      * For each package a Package object is created and stored in $this->packages.
      *
-     * @return array
+     * @return array<string,mixed>
      * @throws Exception
      * @throws InvalidConfigurationException
      */
@@ -483,6 +488,8 @@ protected function scanAvailablePackages(): array
     /**
      * Traverses directories recursively from the given starting point and yields folder paths, who contain a composer.json.
      * When a composer.json was found, traversing into lower directories is stopped.
+     *
+     * @implements \Generator<string>
      */
     protected function findComposerPackagesInPath(string $startingDirectory): \Generator
     {
@@ -508,6 +515,14 @@ protected function findComposerPackagesInPath(string $startingDirectory): \Gener
     /**
      * @throws Exception\CorruptPackageException
      * @throws Exception\InvalidPackagePathException
+     * @param ComposerManifest $composerManifest
+     * @return array{
+     *     packageKey: string,
+     *     packagePath: string,
+     *     composerName: string,
+     *     autoloadConfiguration: array<mixed>,
+     *     packageClassInformation: array<string>,
+     * }
      */
     protected function preparePackageStateConfiguration(FlowPackageKey $packageKey, string $packagePath, array $composerManifest): array
     {
@@ -525,7 +540,7 @@ protected function preparePackageStateConfiguration(FlowPackageKey $packageKey,
     /**
      * Requires and registers all packages which were defined in packageStatesConfiguration
      *
-     * @param array $packageStatesConfiguration
+     * @param array<string,mixed> $packageStatesConfiguration
      * @throws Exception\CorruptPackageException
      */
     protected function registerPackagesFromConfiguration($packageStatesConfiguration): void
@@ -541,7 +556,7 @@ protected function registerPackagesFromConfiguration($packageStatesConfiguration
      * to all relevant data arrays.
      *
      * @param string $composerName
-     * @param array $packageStateConfiguration
+     * @param array<string,mixed> $packageStateConfiguration
      * @return void
      * @throws Exception\CorruptPackageException
      */
@@ -558,8 +573,8 @@ protected function registerPackageFromStateConfiguration($composerName, $package
      * Takes the given packageStatesConfiguration, sorts it by dependencies, saves it and returns
      * the ordered list
      *
-     * @param array $packageStates
-     * @return array
+     * @param array<string,mixed> $packageStates
+     * @return array<string,mixed>
      * @throws Exception\PackageStatesFileNotWritableException
      * @throws FilesException
      */
@@ -574,7 +589,7 @@ protected function sortAndSavePackageStates(array $packageStates): array
     /**
      * Save the given (ordered) array of package states data
      *
-     * @param array $orderedPackageStates
+     * @param array<string,mixed> $orderedPackageStates
      * @throws Exception\PackageStatesFileNotWritableException
      * @throws FilesException
      */
@@ -620,12 +635,15 @@ protected function savePackageStates(array $orderedPackageStates): void
      * and package configurations arrays holds all packages in the correct
      * initialization order.
      *
-     * @param array $packageStates The unordered package states
-     * @return array ordered package states.
+     * @param array<string,mixed> $packageStates The unordered package states
+     * @return array<string,mixed> ordered package states.
      */
     protected function sortAvailablePackagesByDependencies(array $packageStates): array
     {
-        $packageOrderResolver = new PackageOrderResolver($packageStates['packages'], $this->collectPackageManifestData($packageStates));
+        $packageOrderResolver = new PackageOrderResolver(
+            $packageStates['packages'],
+            $this->collectPackageManifestData($packageStates)
+        );
         $packageStates['packages'] = $packageOrderResolver->sort();
 
         return $packageStates;
@@ -634,8 +652,8 @@ protected function sortAvailablePackagesByDependencies(array $packageStates): ar
     /**
      * Collects the manifest data for all packages in the given package states array
      *
-     * @param array $packageStates
-     * @return array
+     * @param array<string,mixed> $packageStates
+     * @return array<string,ComposerManifest>
      */
     protected function collectPackageManifestData(array $packageStates): array
     {
diff --git a/Neos.Flow/Classes/Package/PackageOrderResolver.php b/Neos.Flow/Classes/Package/PackageOrderResolver.php
index 8fae9f6b99..c1f9235be8 100644
--- a/Neos.Flow/Classes/Package/PackageOrderResolver.php
+++ b/Neos.Flow/Classes/Package/PackageOrderResolver.php
@@ -3,21 +3,23 @@
 
 /**
  * A simple package dependency order solver. Just sorts by simple dependencies, does no checking or versions.
+ *
+ * @phpstan-import-type ComposerManifest from PackageManager
  */
 class PackageOrderResolver
 {
     /**
-     * @var array
+     * @var array<string,ComposerManifest>
      */
     protected $manifestData;
 
     /**
-     * @var array
+     * @var array<string,array<string,mixed>>
      */
     protected $packageStates;
 
     /**
-     * @var array
+     * @var array<mixed>
      */
     protected $sortedPackages;
 
@@ -25,13 +27,13 @@ class PackageOrderResolver
      * Array with state information of still unsorted packages.
      * The key is a package key, the value is "-1" if it is on stack for cycle detection; otherwise it is the number of times it was attempted to sort it already.
      *
-     * @var array
+     * @var array<string,int>
      */
     protected $unsortedPackages;
 
     /**
-     * @param array $packages The array of package states to order by dependencies
-     * @param array $manifestData The manifests of all given packages for reading dependencies
+     * @param array<string,array<string,mixed>> $packages The array of package states to order by dependencies
+     * @param array<string,ComposerManifest> $manifestData The manifests of all given packages for reading dependencies
      */
     public function __construct(array $packages, array $manifestData)
     {
@@ -43,7 +45,7 @@ public function __construct(array $packages, array $manifestData)
     /**
      * Sorts the packages and returns the sorted packages array
      *
-     * @return array
+     * @return array<mixed>
      */
     public function sort()
     {
@@ -100,7 +102,6 @@ protected function sortPackage($packageKey)
             $unresolvedDependencies += $this->sortListBefore($packageKey, $sortingConfiguration);
         }
 
-        /** @var array $packageState */
         $packageState = $this->packageStates[$packageKey];
         $this->unsortedPackages[$packageKey] = $iterationForPackage + 1;
         if ($unresolvedDependencies === 0) {
diff --git a/Neos.Flow/Classes/Persistence/AbstractPersistenceManager.php b/Neos.Flow/Classes/Persistence/AbstractPersistenceManager.php
index 2db99302da..c887f1fc75 100644
--- a/Neos.Flow/Classes/Persistence/AbstractPersistenceManager.php
+++ b/Neos.Flow/Classes/Persistence/AbstractPersistenceManager.php
@@ -22,12 +22,12 @@
 abstract class AbstractPersistenceManager implements PersistenceManagerInterface
 {
     /**
-     * @var array
+     * @var array<mixed>
      */
     protected $settings = [];
 
     /**
-     * @var array
+     * @var array<string,Aspect\PersistenceMagicInterface>
      */
     protected $newObjects = [];
 
@@ -46,7 +46,7 @@ abstract class AbstractPersistenceManager implements PersistenceManagerInterface
      * Injects the Flow settings, the persistence part is kept
      * for further use.
      *
-     * @param array $settings
+     * @param array<string,array<mixed>> $settings
      * @return void
      */
     public function injectSettings(array $settings): void
diff --git a/Neos.Flow/Classes/Persistence/AllowedObjectsContainer.php b/Neos.Flow/Classes/Persistence/AllowedObjectsContainer.php
index a013cec08e..c877ce1960 100644
--- a/Neos.Flow/Classes/Persistence/AllowedObjectsContainer.php
+++ b/Neos.Flow/Classes/Persistence/AllowedObjectsContainer.php
@@ -18,6 +18,7 @@
 /**
  * A container for the list of allowed objects to be persisted during this request.
  *
+ * @extends \SplObjectStorage<object,mixed>
  * @Flow\Scope("singleton")
  */
 final class AllowedObjectsContainer extends \SplObjectStorage
diff --git a/Neos.Flow/Classes/Persistence/Aspect/EmbeddedValueObjectPointcutFilter.php b/Neos.Flow/Classes/Persistence/Aspect/EmbeddedValueObjectPointcutFilter.php
index e4526c1003..359e31a0a2 100644
--- a/Neos.Flow/Classes/Persistence/Aspect/EmbeddedValueObjectPointcutFilter.php
+++ b/Neos.Flow/Classes/Persistence/Aspect/EmbeddedValueObjectPointcutFilter.php
@@ -39,7 +39,7 @@ public function injectReflectionService(\Neos\Flow\Reflection\ReflectionService
     /**
      * Checks if the specified class and method matches against the filter
      *
-     * @param string $className Name of the class to check against
+     * @param class-string $className Name of the class to check against
      * @param string $methodName Name of the method to check against
      * @param string $methodDeclaringClassName Name of the class the method was originally declared in
      * @param mixed $pointcutQueryIdentifier Some identifier for this query - must at least differ from a previous identifier. Used for circular reference detection.
@@ -64,7 +64,7 @@ public function hasRuntimeEvaluationsDefinition()
     /**
      * Returns runtime evaluations for a previously matched pointcut
      *
-     * @return array Runtime evaluations
+     * @return array<mixed> Runtime evaluations
      */
     public function getRuntimeEvaluationsDefinition()
     {
diff --git a/Neos.Flow/Classes/Persistence/Aspect/PersistenceMagicAspect.php b/Neos.Flow/Classes/Persistence/Aspect/PersistenceMagicAspect.php
index 7daf1e95dc..46b8d4e506 100644
--- a/Neos.Flow/Classes/Persistence/Aspect/PersistenceMagicAspect.php
+++ b/Neos.Flow/Classes/Persistence/Aspect/PersistenceMagicAspect.php
@@ -49,21 +49,21 @@ class PersistenceMagicAspect
     /**
      * @Flow\Pointcut("classAnnotatedWith(Neos\Flow\Annotations\Entity) || classAnnotatedWith(Doctrine\ORM\Mapping\Entity)")
      */
-    public function isEntity()
+    public function isEntity(): void
     {
     }
 
     /**
      * @Flow\Pointcut("classAnnotatedWith(Neos\Flow\Annotations\ValueObject) && !filter(Neos\Flow\Persistence\Aspect\EmbeddedValueObjectPointcutFilter)")
      */
-    public function isNonEmbeddedValueObject()
+    public function isNonEmbeddedValueObject(): void
     {
     }
 
     /**
      * @Flow\Pointcut("Neos\Flow\Persistence\Aspect\PersistenceMagicAspect->isEntity || Neos\Flow\Persistence\Aspect\PersistenceMagicAspect->isNonEmbeddedValueObject")
      */
-    public function isEntityOrValueObject()
+    public function isEntityOrValueObject(): void
     {
     }
 
@@ -114,6 +114,9 @@ public function generateValueHash(JoinPointInterface $joinPoint)
         $hashSourceParts = [];
 
         $classSchema = $this->reflectionService->getClassSchema($proxyClassName);
+        if (!$classSchema) {
+            throw new \Exception('Missing class schema for proxy class ' . $proxyClassName);
+        }
         foreach ($classSchema->getProperties() as $property => $propertySchema) {
             // Currently, private properties are transient. Should this behaviour change, they need to be included
             // in the value hash generation
@@ -138,6 +141,6 @@ public function generateValueHash(JoinPointInterface $joinPoint)
         $serializedSource = ($this->useIgBinary === true) ? igbinary_serialize($hashSourceParts) : serialize($hashSourceParts);
 
         $proxy = $joinPoint->getProxy();
-        ObjectAccess::setProperty($proxy, 'Persistence_Object_Identifier', sha1($serializedSource), true);
+        ObjectAccess::setProperty($proxy, 'Persistence_Object_Identifier', sha1($serializedSource ?: ''), true);
     }
 }
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/ArrayTypeConverter.php b/Neos.Flow/Classes/Persistence/Doctrine/ArrayTypeConverter.php
index 46bdd4ae3c..0a2de45843 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/ArrayTypeConverter.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/ArrayTypeConverter.php
@@ -63,16 +63,15 @@ class ArrayTypeConverter extends AbstractTypeConverter
      *
      * @param mixed $source
      * @param string $targetType
-     * @param array $convertedChildProperties
-     * @param PropertyMappingConfigurationInterface $configuration
-     * @return mixed|Error the target type, or an error object if a user-error occurred
+     * @param array<string,mixed> $convertedChildProperties
+     * @return array<mixed> the target type, or an error object if a user-error occurred
      * @throws TypeConverterException thrown in case a developer error occurred
      * @api
      */
     public function convertFrom($source, $targetType, array $convertedChildProperties = [], ?PropertyMappingConfigurationInterface $configuration = null)
     {
         $result = [];
-        $convertElements = $configuration->getConfigurationValue(ArrayTypeConverter::class, self::CONFIGURATION_CONVERT_ELEMENTS);
+        $convertElements = $configuration?->getConfigurationValue(ArrayTypeConverter::class, self::CONFIGURATION_CONVERT_ELEMENTS) ?: true;
         foreach ($source as $element) {
             if ($convertElements === true) {
                 $element = $this->propertyMapper->convert($element, 'array', $configuration);
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/CountWalker.php b/Neos.Flow/Classes/Persistence/Doctrine/CountWalker.php
index c1695d1b3a..f98cfeb319 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/CountWalker.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/CountWalker.php
@@ -34,7 +34,7 @@ public function walkSelectStatement(SelectStatement $AST)
         $parent = null;
         $parentName = null;
         foreach ($this->getQueryComponents() as $dqlAlias => $qComp) {
-            if ($qComp['parent'] === null && $qComp['nestingLevel'] === 0) {
+            if (($qComp['parent'] ?? null) === null && $qComp['nestingLevel'] === 0) {
                 $parent = $qComp;
                 $parentName = $dqlAlias;
                 break;
@@ -45,10 +45,13 @@ public function walkSelectStatement(SelectStatement $AST)
             $AST->selectClause->isDistinct = true;
         }
 
+        if (!is_string($parentName)) {
+            throw new \Exception('Missing parent name', 1744138349);
+        }
         $pathExpression = new PathExpression(
             PathExpression::TYPE_STATE_FIELD | PathExpression::TYPE_SINGLE_VALUED_ASSOCIATION,
             $parentName,
-            $parent['metadata']->getSingleIdentifierFieldName()
+            ($parent['metadata'] ?? null)?->getSingleIdentifierFieldName()
         );
         $pathExpression->type = PathExpression::TYPE_STATE_FIELD;
 
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/DataTypes/JsonArrayType.php b/Neos.Flow/Classes/Persistence/Doctrine/DataTypes/JsonArrayType.php
index 33f829684a..111c0c131a 100755
--- a/Neos.Flow/Classes/Persistence/Doctrine/DataTypes/JsonArrayType.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/DataTypes/JsonArrayType.php
@@ -60,7 +60,7 @@ public function getMappedDatabaseTypes(AbstractPlatform $platform): array
      *
      * @param mixed $value The value to convert.
      * @param AbstractPlatform $platform The currently used database platform.
-     * @return array|null The PHP representation of the value.
+     * @return array<mixed>|null The PHP representation of the value.
      * @throws ConversionException
      * @throws TypeConverterException
      */
@@ -124,11 +124,15 @@ protected function initializeDependencies(): void
      * Traverses the $array and replaces known persisted objects (tuples of
      * type and identifier) with actual instances.
      *
+     * @param array<mixed> $array
      * @throws TypeConverterException
      */
     protected function decodeObjectReferences(array &$array): void
     {
-        assert($this->persistenceManager instanceof PersistenceManagerInterface);
+        $persistenceManager = $this->persistenceManager;
+        if (!$persistenceManager) {
+            throw new \Exception('PersistenceManager is missing', 1744138182);
+        }
 
         foreach ($array as &$value) {
             if (!is_array($value)) {
@@ -138,7 +142,7 @@ protected function decodeObjectReferences(array &$array): void
             if (isset($value['__value_object_value'], $value['__value_object_type'])) {
                 $value = self::deserializeValueObject($value);
             } elseif (isset($value['__flow_object_type'])) {
-                $value = $this->persistenceManager->getObjectByIdentifier($value['__identifier'], $value['__flow_object_type'], true);
+                $value = $persistenceManager->getObjectByIdentifier($value['__identifier'], $value['__flow_object_type'], true);
             } else {
                 $this->decodeObjectReferences($value);
             }
@@ -146,6 +150,7 @@ protected function decodeObjectReferences(array &$array): void
     }
 
     /**
+     * @param array<string,mixed> $serializedValueObject
      * @throws \InvalidArgumentException
      * @throws TypeConverterException
      */
@@ -168,12 +173,16 @@ public static function deserializeValueObject(array $serializedValueObject): \Js
      * Traverses the $array and replaces known persisted objects with a tuple of
      * type and identifier.
      *
+     * @param array<mixed> $array
      * @throws \RuntimeException
      * @throws \JsonException
      */
     protected function encodeObjectReferences(array &$array): void
     {
-        assert($this->persistenceManager instanceof PersistenceManagerInterface);
+        $persistenceManager = $this->persistenceManager;
+        if (!$persistenceManager) {
+            throw new \Exception('PersistenceManager is missing', 1744138137);
+        }
 
         foreach ($array as &$value) {
             if (is_array($value)) {
@@ -197,7 +206,7 @@ protected function encodeObjectReferences(array &$array): void
                 throw new \RuntimeException('Collection in array properties is not supported', 1375196581);
             } elseif ($value instanceof \ArrayObject) {
                 throw new \RuntimeException('ArrayObject in array properties is not supported', 1375196582);
-            } elseif ($this->persistenceManager->isNewObject($value) === false
+            } elseif ($persistenceManager->isNewObject($value) === false
                 && (
                     $this->reflectionService->isClassAnnotatedWith($propertyClassName, Flow\Entity::class)
                     || $this->reflectionService->isClassAnnotatedWith($propertyClassName, Flow\ValueObject::class)
@@ -206,7 +215,7 @@ protected function encodeObjectReferences(array &$array): void
             ) {
                 $value = [
                     '__flow_object_type' => $propertyClassName,
-                    '__identifier' => $this->persistenceManager->getIdentifierByObject($value)
+                    '__identifier' => $persistenceManager->getIdentifierByObject($value)
                 ];
             } elseif ($value instanceof \JsonSerializable
                 && DenormalizingObjectConverter::isDenormalizable(get_class($value))
@@ -219,6 +228,7 @@ protected function encodeObjectReferences(array &$array): void
     /**
      * @throws \RuntimeException
      * @throws \JsonException
+     * @return array<string,mixed>
      */
     public static function serializeValueObject(\JsonSerializable $valueObject): array
     {
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/EntityManagerConfiguration.php b/Neos.Flow/Classes/Persistence/Doctrine/EntityManagerConfiguration.php
index 93e19e6942..3225e80660 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/EntityManagerConfiguration.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/EntityManagerConfiguration.php
@@ -99,7 +99,7 @@ public function configureEntityManager(Connection $connection, Configuration $co
     }
 
     /**
-     * @param array $configuredSubscribers
+     * @param array<class-string> $configuredSubscribers
      * @param EventManager $eventManager
      * @throws IllegalObjectTypeException
      */
@@ -115,7 +115,7 @@ protected function registerEventSubscribers(array $configuredSubscribers, EventM
     }
 
     /**
-     * @param array $configuredListeners
+     * @param array<array{listener: class-string<object>, events: string|array<string>}> $configuredListeners
      * @param EventManager $eventManager
      */
     protected function registerEventListeners(array $configuredListeners, EventManager $eventManager): void
@@ -130,7 +130,7 @@ protected function registerEventListeners(array $configuredListeners, EventManag
      * Apply configured settings regarding DQL to the Doctrine Configuration.
      * At the moment, these are custom DQL functions.
      *
-     * @param array $configuredSettings
+     * @param array<string,mixed> $configuredSettings
      * @param Configuration $doctrineConfiguration
      * @return void
      */
@@ -174,7 +174,7 @@ protected function applyCacheConfiguration(Configuration $config): void
     /**
      * Apply configured settings regarding Doctrine's second level cache.
      *
-     * @param array $configuredSettings
+     * @param array<string,mixed> $configuredSettings
      * @param Configuration $doctrineConfiguration
      * @return void
      * @throws NoSuchCacheException
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/EntityManagerFactory.php b/Neos.Flow/Classes/Persistence/Doctrine/EntityManagerFactory.php
index 6380139d5e..3fc9c34544 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/EntityManagerFactory.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/EntityManagerFactory.php
@@ -55,7 +55,7 @@ class EntityManagerFactory
     protected $environment;
 
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $settings = [];
 
@@ -63,7 +63,7 @@ class EntityManagerFactory
      * Injects the Flow settings, the persistence part is kept
      * for further use.
      *
-     * @param array $settings
+     * @param array<string,array<string,mixed>> $settings
      * @return void
      * @throws InvalidConfigurationException
      */
@@ -138,7 +138,7 @@ public function create()
      * @param EventManager $eventManager
      * @Flow\Signal
      */
-    public function emitBeforeDoctrineEntityManagerCreation(Connection $connection, Configuration $config, EventManager $eventManager)
+    public function emitBeforeDoctrineEntityManagerCreation(Connection $connection, Configuration $config, EventManager $eventManager): void
     {
     }
 
@@ -147,7 +147,7 @@ public function emitBeforeDoctrineEntityManagerCreation(Connection $connection,
      * @param EntityManager $entityManager
      * @Flow\Signal
      */
-    public function emitAfterDoctrineEntityManagerCreation(Configuration $config, EntityManager $entityManager)
+    public function emitAfterDoctrineEntityManagerCreation(Configuration $config, EntityManager $entityManager): void
     {
     }
 
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/Mapping/ClassMetadata.php b/Neos.Flow/Classes/Persistence/Doctrine/Mapping/ClassMetadata.php
index 4a9fc7c8dc..5e24fd0d14 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/Mapping/ClassMetadata.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/Mapping/ClassMetadata.php
@@ -17,6 +17,8 @@
 /**
  * A ClassMetadata instance holds all the object-relational mapping metadata
  * of an entity and it's associations.
+ *
+ * @extends \Doctrine\ORM\Mapping\ClassMetadata<object>
  */
 class ClassMetadata extends \Doctrine\ORM\Mapping\ClassMetadata
 {
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/Mapping/ClassMetadataFactory.php b/Neos.Flow/Classes/Persistence/Doctrine/Mapping/ClassMetadataFactory.php
index eecf79fab8..ee630624e4 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/Mapping/ClassMetadataFactory.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/Mapping/ClassMetadataFactory.php
@@ -21,7 +21,7 @@ class ClassMetadataFactory extends \Doctrine\ORM\Mapping\ClassMetadataFactory
     /**
      * Creates a new ClassMetadata instance for the given class name.
      *
-     * @param string $className
+     * @param class-string $className
      * @return ClassMetadata
      */
     protected function newClassMetadataInstance($className)
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/Mapping/Driver/FlowAnnotationDriver.php b/Neos.Flow/Classes/Persistence/Doctrine/Mapping/Driver/FlowAnnotationDriver.php
index 8539422da6..d047a535f5 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/Mapping/Driver/FlowAnnotationDriver.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/Mapping/Driver/FlowAnnotationDriver.php
@@ -14,6 +14,7 @@
 use Doctrine\Common\Annotations\AnnotationReader;
 use Doctrine\Common\Annotations\IndexedReader;
 use Doctrine\Common\Annotations\Reader;
+use Doctrine\ORM\Mapping\MappingAttribute;
 use Doctrine\Persistence\Mapping\ClassMetadata;
 use Doctrine\Persistence\Mapping\Driver\MappingDriver as DoctrineMappingDriverInterface;
 use Doctrine\ORM\EntityManagerInterface;
@@ -70,7 +71,7 @@ class FlowAnnotationDriver implements DoctrineMappingDriverInterface, PointcutFi
     protected $entityManager;
 
     /**
-     * @var array
+     * @var ?array<int,class-string>
      */
     protected $classNames;
 
@@ -126,7 +127,7 @@ protected function getClassSchema($className)
     /**
      * Check for $className being an aggregate root.
      *
-     * @param string $className
+     * @param class-string $className
      * @param string $propertySourceHint
      * @return boolean
      * @throws ClassSchemaNotFoundException
@@ -146,7 +147,7 @@ protected function isAggregateRoot($className, $propertySourceHint)
     /**
      * Check for $className being a value object.
      *
-     * @param string $className
+     * @param class-string $className
      * @param string $propertySourceHint
      * @return boolean
      * @throws ClassSchemaNotFoundException
@@ -166,8 +167,8 @@ protected function isValueObject($className, $propertySourceHint)
     /**
      * Loads the metadata for the specified class into the provided container.
      *
-     * @param string $className
-     * @param ClassMetadata $metadata
+     * @param class-string $className
+     * @param ClassMetadata<object> $metadata
      * @return void
      * @throws ORM\MappingException
      * @throws \UnexpectedValueException
@@ -178,9 +179,8 @@ public function loadMetadataForClass($className, ClassMetadata $metadata)
          * This is the actual type we have at this point, but we cannot change the
          * signature due to inheritance.
          *
-         * @var ORM\ClassMetadata $metadata
+         * @var ORM\ClassMetadata<object> $metadata
          */
-
         try {
             $class = $metadata->getReflectionClass();
             $classSchema = $this->getClassSchema($class->getName());
@@ -191,24 +191,28 @@ public function loadMetadataForClass($className, ClassMetadata $metadata)
 
         // Evaluate Entity annotation
         if (isset($classAnnotations[ORM\MappedSuperclass::class])) {
+            /** @var ORM\MappedSuperclass $mappedSuperclassAnnotation */
             $mappedSuperclassAnnotation = $classAnnotations[ORM\MappedSuperclass::class];
             if ($mappedSuperclassAnnotation->repositoryClass !== null) {
                 $metadata->setCustomRepositoryClass($mappedSuperclassAnnotation->repositoryClass);
             }
             $metadata->isMappedSuperclass = true;
         } elseif (isset($classAnnotations[Flow\Entity::class]) || isset($classAnnotations[ORM\Entity::class])) {
-            $entityAnnotation = isset($classAnnotations[Flow\Entity::class]) ? $classAnnotations[Flow\Entity::class] : $classAnnotations[ORM\Entity::class];
-            if ($entityAnnotation->repositoryClass !== null) {
+            /** @var Flow\Entity|ORM\Entity<object> $entityAnnotation */
+            $entityAnnotation = $classAnnotations[Flow\Entity::class] ?? $classAnnotations[ORM\Entity::class];
+            if ($entityAnnotation->repositoryClass !== null && is_subclass_of($entityAnnotation->repositoryClass, EntityRepository::class)) {
                 $metadata->setCustomRepositoryClass($entityAnnotation->repositoryClass);
             } elseif ($classSchema->getRepositoryClassName() !== null) {
-                if ($this->reflectionService->isClassImplementationOf($classSchema->getRepositoryClassName(), EntityRepository::class)) {
-                    $metadata->setCustomRepositoryClass($classSchema->getRepositoryClassName());
+                $repositoryClassName = $classSchema->getRepositoryClassName();
+                if (is_subclass_of($repositoryClassName, EntityRepository::class)) {
+                    $metadata->setCustomRepositoryClass($repositoryClassName);
                 }
             }
             if ($entityAnnotation->readOnly) {
                 $metadata->markReadOnly();
             }
         } elseif (isset($classAnnotations[Flow\ValueObject::class])) {
+            /** @var Flow\ValueObject $valueObjectAnnotation */
             $valueObjectAnnotation = $classAnnotations[Flow\ValueObject::class];
             if ($valueObjectAnnotation->embedded === true) {
                 $metadata->isEmbeddedClass = true;
@@ -225,6 +229,7 @@ public function loadMetadataForClass($className, ClassMetadata $metadata)
         // Evaluate Table annotation
         $primaryTable = [];
         if (isset($classAnnotations[ORM\Table::class])) {
+            /** @var ORM\Table $tableAnnotation */
             $tableAnnotation = $classAnnotations[ORM\Table::class];
             $primaryTable = [
                 'name' => $tableAnnotation->name,
@@ -276,6 +281,7 @@ public function loadMetadataForClass($className, ClassMetadata $metadata)
 
         // Evaluate @Cache annotation
         if (isset($classAnnotations[ORM\Cache::class])) {
+            /** @var ORM\Cache $cacheAnnotation */
             $cacheAnnotation = $classAnnotations[ORM\Cache::class];
             $cacheMap   = [
                 'region' => $cacheAnnotation->region,
@@ -287,6 +293,7 @@ public function loadMetadataForClass($className, ClassMetadata $metadata)
 
         // Evaluate NamedNativeQueries annotation
         if (isset($classAnnotations[ORM\NamedNativeQueries::class])) {
+            /** @var ORM\NamedNativeQueries $namedNativeQueriesAnnotation */
             $namedNativeQueriesAnnotation = $classAnnotations[ORM\NamedNativeQueries::class];
 
             foreach ($namedNativeQueriesAnnotation->value as $namedNativeQuery) {
@@ -301,6 +308,7 @@ public function loadMetadataForClass($className, ClassMetadata $metadata)
 
         // Evaluate SqlResultSetMappings annotation
         if (isset($classAnnotations[ORM\SqlResultSetMappings::class])) {
+            /** @var ORM\SqlResultSetMappings $sqlResultSetMappingsAnnotation */
             $sqlResultSetMappingsAnnotation = $classAnnotations[ORM\SqlResultSetMappings::class];
 
             foreach ($sqlResultSetMappingsAnnotation->value as $resultSetMapping) {
@@ -339,16 +347,10 @@ public function loadMetadataForClass($className, ClassMetadata $metadata)
 
         // Evaluate NamedQueries annotation
         if (isset($classAnnotations[ORM\NamedQueries::class])) {
+            /** @var ORM\NamedQueries $namedQueriesAnnotation */
             $namedQueriesAnnotation = $classAnnotations[ORM\NamedQueries::class];
 
-            if (!is_array($namedQueriesAnnotation->value)) {
-                throw new \UnexpectedValueException('@ORM\NamedQueries should contain an array of @ORM\NamedQuery annotations.');
-            }
-
             foreach ($namedQueriesAnnotation->value as $namedQuery) {
-                if (!($namedQuery instanceof ORM\NamedQuery)) {
-                    throw new \UnexpectedValueException('@ORM\NamedQueries should contain an array of @ORM\NamedQuery annotations.');
-                }
                 $metadata->addNamedQuery([
                     'name' => $namedQuery->name,
                     'query' => $namedQuery->query
@@ -358,17 +360,19 @@ public function loadMetadataForClass($className, ClassMetadata $metadata)
 
         // Evaluate InheritanceType annotation
         if (isset($classAnnotations[ORM\InheritanceType::class])) {
+            /** @var ORM\InheritanceType $inheritanceTypeAnnotation */
             $inheritanceTypeAnnotation = $classAnnotations[ORM\InheritanceType::class];
             $inheritanceType = constant('Doctrine\ORM\Mapping\ClassMetadata::INHERITANCE_TYPE_' . strtoupper($inheritanceTypeAnnotation->value));
 
             if ($inheritanceType !== ORM\ClassMetadata::INHERITANCE_TYPE_NONE) {
                 // Evaluate DiscriminatorColumn annotation
                 if (isset($classAnnotations[ORM\DiscriminatorColumn::class])) {
+                    /** @var ORM\DiscriminatorColumn $discriminatorColumnAnnotation */
                     $discriminatorColumnAnnotation = $classAnnotations[ORM\DiscriminatorColumn::class];
                     $discriminatorColumn = [
                         'name' => $discriminatorColumnAnnotation->name,
-                        'type' => $discriminatorColumnAnnotation->type,
-                        'length' => $discriminatorColumnAnnotation->length,
+                        'type' => $discriminatorColumnAnnotation->type ?: throw new \Exception('Cannot use untyped discriminator column', 1744137386),
+                        'length' => $discriminatorColumnAnnotation->length ?: throw new \Exception('Cannot use discriminator column without length', 1744137404),
                         'columnDefinition' => $discriminatorColumnAnnotation->columnDefinition
                     ];
                 } else {
@@ -379,6 +383,7 @@ public function loadMetadataForClass($className, ClassMetadata $metadata)
 
                 // Evaluate DiscriminatorMap annotation
                 if (isset($classAnnotations[ORM\DiscriminatorMap::class])) {
+                    /** @var ORM\DiscriminatorMap $discriminatorMapAnnotation */
                     $discriminatorMapAnnotation = $classAnnotations[ORM\DiscriminatorMap::class];
                     $discriminatorMap = $discriminatorMapAnnotation->value;
                 } else {
@@ -407,8 +412,11 @@ public function loadMetadataForClass($className, ClassMetadata $metadata)
 
         // Evaluate DoctrineChangeTrackingPolicy annotation
         if (isset($classAnnotations[ORM\ChangeTrackingPolicy::class])) {
+            /** @var ORM\ChangeTrackingPolicy $changeTrackingAnnotation */
             $changeTrackingAnnotation = $classAnnotations[ORM\ChangeTrackingPolicy::class];
-            $metadata->setChangeTrackingPolicy(constant('Doctrine\ORM\Mapping\ClassMetadata::CHANGETRACKING_' . strtoupper($changeTrackingAnnotation->value)));
+            $metadata->setChangeTrackingPolicy(constant(
+                'Doctrine\ORM\Mapping\ClassMetadata::CHANGETRACKING_' . strtoupper($changeTrackingAnnotation->value)
+            ));
         } else {
             $metadata->setChangeTrackingPolicy(ORM\ClassMetadata::CHANGETRACKING_DEFERRED_EXPLICIT);
         }
@@ -425,7 +433,11 @@ public function loadMetadataForClass($className, ClassMetadata $metadata)
             && !isset($primaryTable['uniqueConstraints'])) {
             $idProperties = array_keys($classSchema->getIdentityProperties());
             if (array_diff($idProperties, $metadata->getIdentifierFieldNames()) !== []) {
-                $uniqueIndexName = $this->truncateIdentifier('flow_identity_' . $primaryTable['name']);
+                $primaryTableName = $primaryTable['name'] ?? null;
+                if (!$primaryTableName) {
+                    throw new \Exception('Missing primary table name', 1744135393);
+                }
+                $uniqueIndexName = $this->truncateIdentifier('flow_identity_' . $primaryTableName);
                 foreach ($idProperties as $idProperty) {
                     $primaryTable['uniqueConstraints'][$uniqueIndexName]['columns'][] = $metadata->fieldMappings[$idProperty]['columnName'] ?? strtolower($idProperty);
                 }
@@ -534,11 +546,11 @@ protected function buildJoinTableColumnName($className)
      * Check if the referenced column name is set (and valid) and if not make sure
      * it is initialized properly.
      *
-     * @param array $joinColumns
-     * @param array $mapping
+     * @param array<mixed> $joinColumns
+     * @param array<mixed> $mapping
      * @param \ReflectionProperty $property
      * @param integer $direction regular or inverse mapping (use is to be coded)
-     * @return array
+     * @return array<mixed>
      */
     protected function buildJoinColumnsIfNeeded(array $joinColumns, array $mapping, \ReflectionProperty $property, $direction = self::MAPPING_REGULAR)
     {
@@ -574,7 +586,7 @@ protected function buildJoinColumnsIfNeeded(array $joinColumns, array $mapping,
     /**
      * Evaluate the property annotations and amend the metadata accordingly.
      *
-     * @param ORM\ClassMetadataInfo $metadata
+     * @param ORM\ClassMetadataInfo<object> $metadata
      * @return void
      * @throws ORM\MappingException
      */
@@ -601,7 +613,7 @@ protected function evaluatePropertyAnnotations(ORM\ClassMetadataInfo $metadata)
             $mapping['fieldName'] = $property->getName();
             $mapping['columnName'] = strtolower($property->getName());
             $mapping['targetEntity'] = $propertyMetaData['type'];
-            $mapping['nullable'] = $propertyMetaData['nullable'] ?? false;
+            $mapping['nullable'] = $propertyMetaData['nullable'];
 
             $joinColumns = $this->evaluateJoinColumnAnnotations($property);
 
@@ -621,13 +633,17 @@ protected function evaluatePropertyAnnotations(ORM\ClassMetadataInfo $metadata)
                 $mapping['inversedBy'] = $oneToOneAnnotation->inversedBy;
                 if ($oneToOneAnnotation->cascade !== null) {
                     $mapping['cascade'] = $oneToOneAnnotation->cascade;
+                    /** @phpstan-ignore argument.type (this really is a class-string -.-) */
                 } elseif ($this->isValueObject($mapping['targetEntity'], $className)) {
                     $mapping['cascade'] = ['persist'];
+                    /** @phpstan-ignore argument.type (this really is a class-string -.-) */
                 } elseif ($this->isAggregateRoot($mapping['targetEntity'], $className) === false) {
                     $mapping['cascade'] = ['all'];
                 }
                 // We need to apply our value for non-aggregate roots first, because Doctrine sets a default value for orphanRemoval (see #1127)
+                /** @phpstan-ignore argument.type (this really is a class-string -.-) */
                 if ($this->isAggregateRoot($mapping['targetEntity'], $className) === false &&
+                    /** @phpstan-ignore argument.type (this really is a class-string -.-) */
                     $this->isValueObject($mapping['targetEntity'], $className) === false) {
                     $mapping['orphanRemoval'] = true;
                 } elseif ($oneToOneAnnotation->orphanRemoval !== null) {
@@ -644,14 +660,18 @@ protected function evaluatePropertyAnnotations(ORM\ClassMetadataInfo $metadata)
                 }
                 if ($oneToManyAnnotation->cascade !== null) {
                     $mapping['cascade'] = $oneToManyAnnotation->cascade;
+                    /** @phpstan-ignore argument.type (this really is a class-string -.-) */
                 } elseif ($this->isValueObject($mapping['targetEntity'], $className)) {
                     $mapping['cascade'] = ['persist'];
+                    /** @phpstan-ignore argument.type (this really is a class-string -.-) */
                 } elseif ($this->isAggregateRoot($mapping['targetEntity'], $className) === false) {
                     $mapping['cascade'] = ['all'];
                 }
                 $mapping['indexBy'] = $oneToManyAnnotation->indexBy;
                 // We need to apply our value for non-aggregate roots first, because Doctrine sets a default value for orphanRemoval (see #1127)
+                /** @phpstan-ignore argument.type (this really is a class-string -.-) */
                 if ($this->isAggregateRoot($mapping['targetEntity'], $className) === false &&
+                    /** @phpstan-ignore argument.type (this really is a class-string -.-) */
                     $this->isValueObject($mapping['targetEntity'], $className) === false) {
                     $mapping['orphanRemoval'] = true;
                 } elseif ($oneToManyAnnotation->orphanRemoval !== null) {
@@ -712,8 +732,10 @@ protected function evaluatePropertyAnnotations(ORM\ClassMetadataInfo $metadata)
                 $mapping['joinColumns'] = $this->buildJoinColumnsIfNeeded($joinColumns, $mapping, $property);
                 if ($manyToOneAnnotation->cascade !== null) {
                     $mapping['cascade'] = $manyToOneAnnotation->cascade;
+                    /** @phpstan-ignore argument.type (this really is a class-string -.-) */
                 } elseif ($this->isValueObject($mapping['targetEntity'], $className)) {
                     $mapping['cascade'] = ['persist'];
+                    /** @phpstan-ignore argument.type (this really is a class-string -.-) */
                 } elseif ($this->isAggregateRoot($mapping['targetEntity'], $className) === false) {
                     $mapping['cascade'] = ['all'];
                 }
@@ -749,8 +771,10 @@ protected function evaluatePropertyAnnotations(ORM\ClassMetadataInfo $metadata)
                 $mapping['inversedBy'] = $manyToManyAnnotation->inversedBy;
                 if ($manyToManyAnnotation->cascade !== null) {
                     $mapping['cascade'] = $manyToManyAnnotation->cascade;
+                    /** @phpstan-ignore argument.type (this really is a class-string -.-) */
                 } elseif ($this->isValueObject($mapping['targetEntity'], $className)) {
                     $mapping['cascade'] = ['persist'];
+                    /** @phpstan-ignore argument.type (this really is a class-string -.-) */
                 } elseif ($this->isAggregateRoot($mapping['targetEntity'], $className) === false) {
                     $mapping['cascade'] = ['all'];
                 }
@@ -798,7 +822,7 @@ protected function evaluatePropertyAnnotations(ORM\ClassMetadataInfo $metadata)
                             break;
                         default:
                             if (strpos($propertyMetaData['type'], '\\') !== false) {
-                                if ($this->reflectionService->isClassAnnotatedWith($propertyMetaData['type'], Flow\ValueObject::class)) {
+                                if (class_exists($propertyMetaData['type']) && $this->reflectionService->isClassAnnotatedWith($propertyMetaData['type'], Flow\ValueObject::class)) {
                                     $valueObjectAnnotation = $this->reflectionService->getClassAnnotation($propertyMetaData['type'], Flow\ValueObject::class);
                                     if ($valueObjectAnnotation && $valueObjectAnnotation->embedded === true) {
                                         $mapping['class'] = $propertyMetaData['type'];
@@ -833,11 +857,11 @@ protected function evaluatePropertyAnnotations(ORM\ClassMetadataInfo $metadata)
 
                 // Check for SequenceGenerator/TableGenerator definition
                 if ($seqGeneratorAnnotation = $this->reader->getPropertyAnnotation($property, ORM\SequenceGenerator::class)) {
-                    $metadata->setSequenceGeneratorDefinition([
+                    $metadata->setSequenceGeneratorDefinition(array_filter([
                         'sequenceName' => $seqGeneratorAnnotation->sequenceName,
                         'allocationSize' => $seqGeneratorAnnotation->allocationSize,
                         'initialValue' => $seqGeneratorAnnotation->initialValue
-                    ]);
+                    ]));
                 } elseif ($customGeneratorAnnotation = $this->reader->getPropertyAnnotation($property, ORM\CustomIdGenerator::class)) {
                     $metadata->setCustomGeneratorDefinition([
                         'class' => $customGeneratorAnnotation->class
@@ -847,10 +871,10 @@ protected function evaluatePropertyAnnotations(ORM\ClassMetadataInfo $metadata)
 
             // Evaluate @Cache annotation
             if (($cacheAnnotation = $this->reader->getPropertyAnnotation($property, ORM\Cache::class)) !== null) {
-                $metadata->enableAssociationCache($mapping['fieldName'], [
-                    'usage'         => constant('Doctrine\ORM\Mapping\ClassMetadata::CACHE_USAGE_' . $cacheAnnotation->usage),
-                    'region'        => $cacheAnnotation->region,
-                ]);
+                $metadata->enableAssociationCache($mapping['fieldName'], array_filter([
+                    'usage' => constant('Doctrine\ORM\Mapping\ClassMetadata::CACHE_USAGE_' . $cacheAnnotation->usage),
+                    'region' => $cacheAnnotation->region,
+                ]));
             }
         }
     }
@@ -861,8 +885,8 @@ protected function evaluatePropertyAnnotations(ORM\ClassMetadataInfo $metadata)
      * @param ORM\JoinTable $joinTableAnnotation
      * @param \ReflectionProperty $property
      * @param string $className
-     * @param array $mapping
-     * @return array
+     * @param array<mixed> $mapping
+     * @return array{name: string, schema: ?string, joinColumns: array<int,mixed>, inverseJoinColumns: array<int,mixed>}
      */
     protected function evaluateJoinTableAnnotation(ORM\JoinTable $joinTableAnnotation, \ReflectionProperty $property, $className, array $mapping)
     {
@@ -908,12 +932,12 @@ protected function evaluateJoinTableAnnotation(ORM\JoinTable $joinTableAnnotatio
     }
 
     /**
-     * Check for and build JoinColummn/JoinColumns annotations.
+     * Check for and build JoinColumn/JoinColumns annotations.
      *
      * If no annotations are found, a default is returned.
      *
      * @param \ReflectionProperty $property
-     * @return array
+     * @return array<int,array<mixed>>
      */
     protected function evaluateJoinColumnAnnotations(\ReflectionProperty $property)
     {
@@ -933,8 +957,8 @@ protected function evaluateJoinColumnAnnotations(\ReflectionProperty $property)
     /**
      * Evaluate the association overrides annotations and amend the metadata accordingly.
      *
-     * @param array $classAnnotations
-     * @param ORM\ClassMetadataInfo $metadata
+     * @param array<mixed> $classAnnotations
+     * @param ORM\ClassMetadataInfo<object> $metadata
      * @return void
      */
     protected function evaluateOverridesAnnotations(array $classAnnotations, ORM\ClassMetadataInfo $metadata)
@@ -992,9 +1016,9 @@ protected function evaluateOverridesAnnotations(array $classAnnotations, ORM\Cla
     /**
      * Evaluate the EntityListeners annotation and amend the metadata accordingly.
      *
-     * @param \ReflectionClass $class
-     * @param ORM\ClassMetadata $metadata
-     * @param array $classAnnotations
+     * @param \ReflectionClass<object> $class
+     * @param ORM\ClassMetadata<object> $metadata
+     * @param array<mixed> $classAnnotations
      * @return void
      * @throws ORM\MappingException
      */
@@ -1007,7 +1031,7 @@ protected function evaluateEntityListenersAnnotation(\ReflectionClass $class, OR
                 $listenerClassName = $metadata->fullyQualifiedClassName($item);
 
                 if ($listenerClassName === null || !class_exists($listenerClassName)) {
-                    throw ORM\MappingException::entityListenerClassNotFound($listenerClassName, $class->getName());
+                    throw ORM\MappingException::entityListenerClassNotFound($listenerClassName ?: 'null', $class->getName());
                 }
 
                 $hasMapping = false;
@@ -1034,8 +1058,8 @@ protected function evaluateEntityListenersAnnotation(\ReflectionClass $class, OR
     /**
      * Evaluate the lifecycle annotations and amend the metadata accordingly.
      *
-     * @param \ReflectionClass $class
-     * @param ORM\ClassMetadataInfo $metadata
+     * @param \ReflectionClass<object> $class
+     * @param ORM\ClassMetadataInfo<object> $metadata
      * @return void
      */
     protected function evaluateLifeCycleAnnotations(\ReflectionClass $class, ORM\ClassMetadataInfo $metadata)
@@ -1058,7 +1082,7 @@ protected function evaluateLifeCycleAnnotations(\ReflectionClass $class, ORM\Cla
      * Returns an array of callbacks for lifecycle annotations on the given method.
      *
      * @param \ReflectionMethod $method
-     * @return array
+     * @return array<int,array<int,mixed>>
      */
     protected function getMethodCallbacks(\ReflectionMethod $method)
     {
@@ -1138,7 +1162,7 @@ public function isTransient($className)
     /**
      * Returns the names of all mapped (non-transient) classes known to this driver.
      *
-     * @return array
+     * @return array<int,class-string>
      */
     public function getAllClassNames()
     {
@@ -1169,7 +1193,7 @@ function ($className) {
      *
      * @param ORM\JoinColumn $joinColumnAnnotation
      * @param string $propertyName
-     * @return array
+     * @return array{name: ?string, unique: bool, nullable: bool, onDelete: mixed, columnDefinition: ?string, referencedColumnName: string}
      */
     protected function joinColumnToArray(ORM\JoinColumn $joinColumnAnnotation, $propertyName = null)
     {
@@ -1187,9 +1211,9 @@ protected function joinColumnToArray(ORM\JoinColumn $joinColumnAnnotation, $prop
      * Parse the given Column into an array
      *
      * @param ORM\Column $columnAnnotation
-     * @param array $mapping
+     * @param array<string,mixed> $mapping
      * @param string $fieldName
-     * @return array
+     * @return array<string,mixed>
      */
     protected function addColumnToMappingArray(ORM\Column $columnAnnotation, array $mapping = [], $fieldName = null)
     {
@@ -1222,11 +1246,12 @@ protected function addColumnToMappingArray(ORM\Column $columnAnnotation, array $
     /**
      * Returns the classname after stripping a potentially present Compiler::ORIGINAL_CLASSNAME_SUFFIX.
      *
-     * @param string $className
-     * @return string
+     * @param class-string $className
+     * @return class-string
      */
     protected function getUnproxiedClassName($className)
     {
+        /** @var class-string $className */
         $className = preg_replace('/' . Compiler::ORIGINAL_CLASSNAME_SUFFIX . '$/', '', $className);
 
         return $className;
@@ -1253,7 +1278,7 @@ private function getFetchMode($className, $fetchMode)
     /**
      * Checks if the specified class has a property annotated with Id
      *
-     * @param string $className Name of the class to check against
+     * @param class-string $className Name of the class to check against
      * @param string $methodName Name of the method to check against
      * @param string $methodDeclaringClassName Name of the class the method was originally declared in
      * @param mixed $pointcutQueryIdentifier Some identifier for this query - must at least differ from a previous identifier. Used for circular reference detection.
@@ -1284,7 +1309,7 @@ public function hasRuntimeEvaluationsDefinition()
     /**
      * Returns runtime evaluations for a previously matched pointcut
      *
-     * @return array Runtime evaluations
+     * @return array<mixed> Runtime evaluations
      */
     public function getRuntimeEvaluationsDefinition()
     {
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/MigrationFinder.php b/Neos.Flow/Classes/Persistence/Doctrine/MigrationFinder.php
index 93555a066c..ced9438bae 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/MigrationFinder.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/MigrationFinder.php
@@ -45,7 +45,7 @@ public function findMigrations(string $directory, ?string $namespace = null): ar
                 $this->databasePlatformName
             ]);
             if (is_dir($path)) {
-                $files[] = glob($path . '/Version*.php');
+                $files[] = glob($path . '/Version*.php') ?: [];
             }
         }
 
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/ObjectValidationAndDeDuplicationListener.php b/Neos.Flow/Classes/Persistence/Doctrine/ObjectValidationAndDeDuplicationListener.php
index 92881f78b5..6732468bea 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/ObjectValidationAndDeDuplicationListener.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/ObjectValidationAndDeDuplicationListener.php
@@ -143,7 +143,7 @@ private function deduplicateValueObjectInsertions()
      * Validates the given object and throws an exception if validation fails.
      *
      * @param object $object
-     * @param \SplObjectStorage $validatedInstancesContainer
+     * @param \SplObjectStorage<object,mixed> $validatedInstancesContainer
      * @return void
      * @throws ObjectValidationFailedException
      */
@@ -151,21 +151,18 @@ private function validateObject($object, \SplObjectStorage $validatedInstancesCo
     {
         $className = $this->entityManager->getClassMetadata(get_class($object))->getName();
         $validator = $this->validatorResolver->getBaseValidatorConjunction($className, ['Persistence', 'Default']);
-        if ($validator === null) {
-            return;
-        }
 
         $validator->setValidatedInstancesContainer($validatedInstancesContainer);
         $validationResult = $validator->validate($object);
-        if ($validationResult->hasErrors()) {
+        if ($validationResult?->hasErrors()) {
             $errorMessages = '';
             $errorCount = 0;
-            $allErrors = $validationResult->getFlattenedErrors();
+            $allErrors = $validationResult->getFlattenedErrors() ?: [];
             foreach ($allErrors as $path => $errors) {
                 $errorMessages .= $path . ':' . PHP_EOL;
                 foreach ($errors as $error) {
                     $errorCount++;
-                    $errorMessages .= (string)$error . PHP_EOL;
+                    $errorMessages .= $error . PHP_EOL;
                 }
             }
             throw new ObjectValidationFailedException('An instance of "' . get_class($object) . '" failed to pass validation with ' . $errorCount . ' error(s): ' . PHP_EOL . $errorMessages, 1322585164);
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/PersistenceManager.php b/Neos.Flow/Classes/Persistence/Doctrine/PersistenceManager.php
index be1c1127c3..9be04cdcef 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/PersistenceManager.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/PersistenceManager.php
@@ -151,7 +151,7 @@ public function clearState(): void
      */
     public function isNewObject($object): bool
     {
-        if (!$object instanceof PersistenceMagicInterface) {
+        if (!($object instanceof PersistenceMagicInterface)) {
             return true;
         }
 
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/Query.php b/Neos.Flow/Classes/Persistence/Doctrine/Query.php
index 62ddd3ed8a..44592cb81d 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/Query.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/Query.php
@@ -64,7 +64,7 @@ class Query implements QueryInterface
     protected $entityManager;
 
     /**
-     * @var array
+     * @var array<mixed>
      */
     protected $settings;
 
@@ -74,7 +74,7 @@ class Query implements QueryInterface
     protected $constraint;
 
     /**
-     * @var array
+     * @var array<string,QueryInterface::ORDER_ASCENDING|QueryInterface::ORDER_DESCENDING>
      */
     protected $orderings = [];
 
@@ -104,7 +104,7 @@ class Query implements QueryInterface
     protected $parameters;
 
     /**
-     * @var array
+     * @var ?array<string,string>
      */
     protected $joins;
 
@@ -140,10 +140,10 @@ public function injectEntityManager(EntityManagerInterface $entityManager)
      * Injects the Flow settings, the persistence part is kept
      * for further use.
      *
-     * @param array $settings
+     * @param array<string,mixed> $settings
      * @return void
      */
-    public function injectSettings(array $settings)
+    public function injectSettings(array $settings): void
     {
         $this->settings = $settings['persistence'];
     }
@@ -151,7 +151,7 @@ public function injectSettings(array $settings)
     /**
      * @param LoggerInterface $logger
      */
-    public function injectLogger(LoggerInterface $logger)
+    public function injectLogger(LoggerInterface $logger): void
     {
         $this->logger = $logger;
     }
@@ -186,7 +186,7 @@ public function execute(bool $cacheResult = false): QueryResultInterface
      * Really executes the query on the database.
      * This should only ever be executed from the QueryResult class.
      *
-     * @return array result set
+     * @return mixed result set
      * @throws DatabaseException
      * @throws DatabaseConnectionException
      * @throws DatabaseStructureException
@@ -283,7 +283,7 @@ public function count(): int
      *  'bar' => \Neos\Flow\Persistence\QueryInterface::ORDER_DESCENDING
      * )
      *
-     * @param array $orderings The property names to order by
+     * @param array<string,QueryInterface::ORDER_ASCENDING|QueryInterface::ORDER_DESCENDING> $orderings The property names to order by
      * @return QueryInterface
      * @api
      */
@@ -304,7 +304,7 @@ public function setOrderings(array $orderings): QueryInterface
      *  'bar' => \Neos\Flow\Persistence\QueryInterface::ORDER_DESCENDING
      * )
      *
-     * @return array
+     * @return array<string,QueryInterface::ORDER_ASCENDING|QueryInterface::ORDER_DESCENDING>
      * @api
      */
     public function getOrderings(): array
@@ -393,7 +393,7 @@ public function getOffset(): ?int
      * The constraint used to limit the result set. Returns $this to allow
      * for chaining (fluid interface)
      *
-     * @param object $constraint Some constraint, depending on the backend
+     * @param object|string $constraint Some constraint, depending on the backend
      * @return QueryInterface
      * @api
      */
@@ -456,7 +456,7 @@ public function logicalOr(mixed $constraint1, mixed ...$constraints)
     /**
      * Performs a logical negation of the given constraint
      *
-     * @param object $constraint Constraint to negate
+     * @param object|string $constraint Constraint to negate
      * @return object
      * @api
      */
@@ -618,7 +618,7 @@ public function greaterThanOrEqual(string $propertyName, $operand)
     /**
      * Add parameters to the query
      *
-     * @param array $parameters
+     * @param array<mixed> $parameters
      * @return void
      */
     public function addParameters($parameters)
@@ -632,7 +632,7 @@ public function addParameters($parameters)
     /**
      * Gets all defined query parameters for the query being constructed.
      *
-     * @return ArrayCollection
+     * @return ArrayCollection<int,Parameter>
      */
     public function getParameters()
     {
@@ -717,7 +717,7 @@ public function __wakeup()
             $this->queryBuilder->where($this->constraint);
         }
 
-        if (is_array($this->orderings)) {
+        if ($this->orderings !== []) {
             $aliases = $this->queryBuilder->getRootAliases();
             foreach ($this->orderings as $propertyName => $order) {
                 $this->queryBuilder->addOrderBy($aliases[0] . '.' . $propertyName, $order);
@@ -732,7 +732,7 @@ public function __wakeup()
         $this->queryBuilder->setMaxResults($this->limit);
         $this->queryBuilder->distinct($this->distinct);
         $this->queryBuilder->setParameters($this->parameters);
-        unset($this->parameters);
+        $this->parameters = new ArrayCollection();
     }
 
     /**
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/QueryResult.php b/Neos.Flow/Classes/Persistence/Doctrine/QueryResult.php
index e8004a88ab..a97d42307b 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/QueryResult.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/QueryResult.php
@@ -23,7 +23,7 @@
 class QueryResult implements QueryResultInterface
 {
     /**
-     * @var array
+     * @var ?array<mixed>
      * @Flow\Transient
      */
     protected $rows;
@@ -50,6 +50,7 @@ public function __construct(Query $query)
     /**
      * Loads the objects this QueryResult is supposed to hold
      *
+     * @phpstan-assert array<mixed> $this->rows
      * @return void
      */
     protected function initialize()
@@ -110,7 +111,7 @@ public function count(): int
     /**
      * Returns an array with the objects in the result set
      *
-     * @return array
+     * @return array<mixed>
      * @api
      */
     public function toArray(): array
@@ -209,6 +210,6 @@ public function rewind(): void
     public function valid(): bool
     {
         $this->initialize();
-        return current($this->rows) !== false;
+        return current($this->rows ?: []) !== false;
     }
 }
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/Repository.php b/Neos.Flow/Classes/Persistence/Doctrine/Repository.php
index 5749463bea..87017f174f 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/Repository.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/Repository.php
@@ -13,8 +13,8 @@
 
 use Doctrine\ORM\EntityManagerInterface;
 use Doctrine\ORM\EntityRepository;
+use Doctrine\ORM\Mapping\ClassMetadata;
 use Doctrine\ORM\QueryBuilder;
-use Doctrine\Persistence\Mapping\ClassMetadata;
 use Neos\Flow\Annotations as Flow;
 use Neos\Flow\Persistence\Exception\IllegalObjectTypeException;
 use Neos\Flow\Persistence\Exception\UnknownObjectException;
@@ -26,6 +26,7 @@
 /**
  * The Flow default Repository, based on Doctrine 2
  *
+ * @extends EntityRepository<object>
  * @api
  */
 abstract class Repository extends EntityRepository implements RepositoryInterface
@@ -50,7 +51,7 @@ abstract class Repository extends EntityRepository implements RepositoryInterfac
     protected $objectType;
 
     /**
-     * @var array
+     * @var array<string,QueryInterface::ORDER_ASCENDING|QueryInterface::ORDER_DESCENDING>
      */
     protected $defaultOrderings = [];
 
@@ -58,7 +59,7 @@ abstract class Repository extends EntityRepository implements RepositoryInterfac
      * Initializes a new Repository.
      *
      * @param EntityManagerInterface $entityManager The EntityManager to use.
-     * @param ClassMetadata|null $classMetadata The class descriptor.
+     * @param ClassMetadata<object>|null $classMetadata The class descriptor.
      */
     public function __construct(EntityManagerInterface $entityManager, ?ClassMetadata $classMetadata = null)
     {
@@ -70,8 +71,12 @@ public function __construct(EntityManagerInterface $entityManager, ?ClassMetadat
             }
             /** @var class-string $objectType */
             $this->objectType = $objectType;
+            /** @var ?ClassMetadata<object> $classMetadata */
             $classMetadata = $entityManager->getClassMetadata($this->objectType);
         }
+        if (!$classMetadata) {
+            throw new \Exception('Unable to resolve class metadata for ' . $this->objectType);
+        }
         parent::__construct($entityManager, $classMetadata);
         $this->entityManager = $this->_em;
     }
@@ -97,9 +102,8 @@ public function getEntityClassName(): string
      */
     public function add($object): void
     {
-        if (!is_object($object) || !($object instanceof $this->objectType)) {
-            $type = (is_object($object) ? get_class($object) : gettype($object));
-            throw new IllegalObjectTypeException('The value given to add() was ' . $type . ' , however the ' . get_class($this) . ' can only store ' . $this->objectType . ' instances.', 1517408062);
+        if (!($object instanceof $this->objectType)) {
+            throw new IllegalObjectTypeException('The value given to add() was ' . get_class($object) . ' , however the ' . get_class($this) . ' can only store ' . $this->objectType . ' instances.', 1517408062);
         }
         $this->entityManager->persist($object);
     }
@@ -114,9 +118,8 @@ public function add($object): void
      */
     public function remove($object): void
     {
-        if (!is_object($object) || !($object instanceof $this->objectType)) {
-            $type = (is_object($object) ? get_class($object) : gettype($object));
-            throw new IllegalObjectTypeException('The value given to remove() was ' . $type . ' , however the ' . get_class($this) . ' can only handle ' . $this->objectType . ' instances.', 1517408067);
+        if (!($object instanceof $this->objectType)) {
+            throw new IllegalObjectTypeException('The value given to remove() was ' . get_class($object) . ' , however the ' . get_class($this) . ' can only handle ' . $this->objectType . ' instances.', 1517408067);
         }
         $this->entityManager->remove($object);
     }
@@ -124,9 +127,10 @@ public function remove($object): void
     /**
      * Finds all entities in the repository.
      *
-     * @phpstan-ignore-next-line we don't satisfy the contract of doctrines repository as we don't return a simple array.
-     * @return QueryResultInterface The query result
+     * @return QueryResultInterface<object> The query result
      * @api
+     * (don't know how generics work here yet and ignoring method.childReturnType has no effect)
+     * @phpstan-ignore-next-line
      */
     public function findAll(): QueryResultInterface
     {
@@ -136,7 +140,7 @@ public function findAll(): QueryResultInterface
     /**
      * Find all objects and return an IterableResult
      *
-     * @return iterable
+     * @return iterable<object>
      */
     public function findAllIterator(): iterable
     {
@@ -222,7 +226,7 @@ public function removeAll(): void
      *  'bar' => \Neos\Flow\Persistence\QueryInterface::ORDER_DESCENDING
      * )
      *
-     * @param array $defaultOrderings The property names to order by by default
+     * @param array<string,QueryInterface::ORDER_ASCENDING|QueryInterface::ORDER_DESCENDING> $defaultOrderings The property names to order by by default
      * @return void
      * @api
      */
@@ -257,7 +261,7 @@ public function update($object): void
      *  - countBy<PropertyName>($value, $caseSensitive = true)
      *
      * @param string $method Name of the method
-     * @param array $arguments The arguments
+     * @param array<mixed> $arguments The arguments
      * @return mixed The result of the repository method
      * @api
      */
diff --git a/Neos.Flow/Classes/Persistence/Doctrine/Service.php b/Neos.Flow/Classes/Persistence/Doctrine/Service.php
index 2c18e36a20..c3d3496588 100644
--- a/Neos.Flow/Classes/Persistence/Doctrine/Service.php
+++ b/Neos.Flow/Classes/Persistence/Doctrine/Service.php
@@ -42,6 +42,7 @@
 use Doctrine\Migrations\Version\ExecutionResult;
 use Doctrine\Migrations\Version\Version;
 use Doctrine\ORM\EntityManagerInterface;
+use Doctrine\ORM\Mapping\ClassMetadata;
 use Doctrine\ORM\Mapping\MappingException;
 use Doctrine\ORM\Tools\SchemaTool;
 use Doctrine\ORM\Tools\SchemaValidator;
@@ -97,7 +98,7 @@ class Service
      * Validates the metadata mapping for Doctrine, using the SchemaValidator
      * of Doctrine.
      *
-     * @return array
+     * @return array<int|string,array<string>>
      */
     public function validateMapping(): array
     {
@@ -167,7 +168,7 @@ public function compileProxies(): void
      * Returns information about which entities exist and possibly if their
      * mapping information contains errors or not.
      *
-     * @return array
+     * @return array<class-string,string|ClassMetadata<object>>
      */
     public function getEntityStatus(): array
     {
@@ -192,12 +193,12 @@ public function getEntityStatus(): array
      * Run DQL and return the result as-is.
      *
      * @param string $dql
-     * @param integer $hydrationMode
+     * @param 1|2|3|4|5|6|string|null $hydrationMode
      * @param int|null $firstResult
      * @param int|null $maxResult
      * @return mixed
      */
-    public function runDql(string $dql, int $hydrationMode = \Doctrine\ORM\Query::HYDRATE_OBJECT, ?int $firstResult = null, ?int $maxResult = null)
+    public function runDql(string $dql, int|string|null $hydrationMode = \Doctrine\ORM\Query::HYDRATE_OBJECT, ?int $firstResult = null, ?int $maxResult = null)
     {
         $query = $this->entityManager->createQuery($dql);
         if ($firstResult !== null) {
@@ -489,7 +490,7 @@ public function markAsMigrated(string $version, bool $markAsMigrated, ?string $o
         if ($version === 'all') {
             if ($markAsMigrated === false) {
                 foreach ($executedMigrations->getItems() as $availableMigration) {
-                    $this->mark($output, $availableMigration->getVersion(), false, $executedMigrations, !$markAsMigrated, $overrideMigrationFolderName);
+                    $this->mark($output, $availableMigration->getVersion(), false, $executedMigrations, true, $overrideMigrationFolderName);
                 }
             }
 
@@ -619,7 +620,7 @@ public function getMigrationStatus(?string $overrideMigrationFolderName = null):
      * @param boolean $diffAgainstCurrent
      * @param string|null $filterExpression
      * @param string|null $overrideMigrationFolderName
-     * @return array Path to the new file
+     * @return array<int,mixed> Path to the new file
      * @throws DBALException
      * @throws FilesException
      */
@@ -694,10 +695,10 @@ public function getMigrationFolderName(): string
      *
      * @param Schema $schema
      * @param AbstractPlatform $platform
-     * @param array $tableNames
+     * @param array<string> $tableNames
      * @param string $search
      * @param string $replace
-     * @return array
+     * @return array{drop: array<int,string>, add: array<int,string>}
      */
     public static function getForeignKeyHandlingSql(Schema $schema, AbstractPlatform $platform, array $tableNames, string $search, string $replace): array
     {
diff --git a/Neos.Flow/Classes/Persistence/EmptyQueryResult.php b/Neos.Flow/Classes/Persistence/EmptyQueryResult.php
index ce291f11d6..3f1e5ed430 100644
--- a/Neos.Flow/Classes/Persistence/EmptyQueryResult.php
+++ b/Neos.Flow/Classes/Persistence/EmptyQueryResult.php
@@ -58,7 +58,7 @@ public function getFirst()
     /**
      * Returns an empty array
      *
-     * @return array
+     * @return array<mixed>
      * @api
      */
     public function toArray(): array
@@ -68,6 +68,7 @@ public function toArray(): array
 
     public function current(): mixed
     {
+        /** @phpstan-ignore return.type (I don't see any "object" requirement here) */
         return null;
     }
 
diff --git a/Neos.Flow/Classes/Persistence/PersistenceManagerInterface.php b/Neos.Flow/Classes/Persistence/PersistenceManagerInterface.php
index 5aff47fa89..80888fb1e6 100644
--- a/Neos.Flow/Classes/Persistence/PersistenceManagerInterface.php
+++ b/Neos.Flow/Classes/Persistence/PersistenceManagerInterface.php
@@ -22,7 +22,7 @@ interface PersistenceManagerInterface
     /**
      * Injects the Flow settings, called by Flow.
      *
-     * @param array $settings
+     * @param array<string,mixed> $settings
      * @return void
      * @api
      */
diff --git a/Neos.Flow/Classes/Persistence/QueryInterface.php b/Neos.Flow/Classes/Persistence/QueryInterface.php
index 910f37d9d8..f7d6334bae 100644
--- a/Neos.Flow/Classes/Persistence/QueryInterface.php
+++ b/Neos.Flow/Classes/Persistence/QueryInterface.php
@@ -129,7 +129,7 @@ public function count(): int;
      *  'bar' => \Neos\Flow\Persistence\QueryInterface::ORDER_DESCENDING
      * )
      *
-     * @param array $orderings The property names to order by
+     * @param array<string,QueryInterface::ORDER_ASCENDING|QueryInterface::ORDER_DESCENDING> $orderings The property names to order by
      * @return QueryInterface
      * @api
      */
@@ -142,7 +142,7 @@ public function setOrderings(array $orderings): QueryInterface;
      *  'bar' => \Neos\Flow\Persistence\QueryInterface::ORDER_DESCENDING
      * )
      *
-     * @return array
+     * @return array<string,QueryInterface::ORDER_ASCENDING|QueryInterface::ORDER_DESCENDING>
      * @api
      */
     public function getOrderings(): array;
diff --git a/Neos.Flow/Classes/Persistence/QueryResultInterface.php b/Neos.Flow/Classes/Persistence/QueryResultInterface.php
index 001d247753..1c260a280f 100644
--- a/Neos.Flow/Classes/Persistence/QueryResultInterface.php
+++ b/Neos.Flow/Classes/Persistence/QueryResultInterface.php
@@ -14,6 +14,8 @@
 /**
  * A lazy result list that is returned by Query::execute()
  *
+ * @extends \Iterator<mixed,object>
+ * @extends \ArrayAccess<mixed,object>
  * @api
  */
 interface QueryResultInterface extends \Countable, \Iterator, \ArrayAccess
@@ -37,7 +39,7 @@ public function getFirst();
     /**
      * Returns an array with the objects in the result set
      *
-     * @return array
+     * @return array<mixed>
      * @api
      */
     public function toArray(): array;
diff --git a/Neos.Flow/Classes/Persistence/Repository.php b/Neos.Flow/Classes/Persistence/Repository.php
index cea6418226..3ace4da0cf 100644
--- a/Neos.Flow/Classes/Persistence/Repository.php
+++ b/Neos.Flow/Classes/Persistence/Repository.php
@@ -36,7 +36,7 @@ abstract class Repository implements RepositoryInterface
     protected $entityClassName;
 
     /**
-     * @var array
+     * @var array<string,QueryInterface::ORDER_ASCENDING|QueryInterface::ORDER_DESCENDING>
      */
     protected $defaultOrderings = [];
 
@@ -78,9 +78,8 @@ public function getEntityClassName(): string
      */
     public function add($object): void
     {
-        if (!is_object($object) || !($object instanceof $this->entityClassName)) {
-            $type = (is_object($object) ? get_class($object) : gettype($object));
-            throw new IllegalObjectTypeException('The value given to add() was ' . $type . ' , however the ' . get_class($this) . ' can only store ' . $this->entityClassName . ' instances.', 1298403438);
+        if (!($object instanceof $this->entityClassName)) {
+            throw new IllegalObjectTypeException('The value given to add() was ' . get_class($object) . ' , however the ' . get_class($this) . ' can only store ' . $this->entityClassName . ' instances.', 1298403438);
         }
         $this->persistenceManager->add($object);
     }
@@ -95,9 +94,8 @@ public function add($object): void
      */
     public function remove($object): void
     {
-        if (!is_object($object) || !($object instanceof $this->entityClassName)) {
-            $type = (is_object($object) ? get_class($object) : gettype($object));
-            throw new IllegalObjectTypeException('The value given to remove() was ' . $type . ' , however the ' . get_class($this) . ' can only handle ' . $this->entityClassName . ' instances.', 1298403442);
+        if (!($object instanceof $this->entityClassName)) {
+            throw new IllegalObjectTypeException('The value given to remove() was ' . get_class($object) . ' , however the ' . get_class($this) . ' can only handle ' . $this->entityClassName . ' instances.', 1298403442);
         }
         $this->persistenceManager->remove($object);
     }
@@ -174,7 +172,7 @@ public function removeAll(): void
      *  'bar' => \Neos\Flow\Persistence\QueryInterface::ORDER_DESCENDING
      * )
      *
-     * @param array $defaultOrderings The property names to order by by default
+     * @param array<string,QueryInterface::ORDER_ASCENDING|QueryInterface::ORDER_DESCENDING> $defaultOrderings The property names to order by by default
      * @return void
      * @api
      */
@@ -192,9 +190,8 @@ public function setDefaultOrderings(array $defaultOrderings): void
      */
     public function update($object): void
     {
-        if (!is_object($object) || !($object instanceof $this->entityClassName)) {
-            $type = (is_object($object) ? get_class($object) : gettype($object));
-            throw new IllegalObjectTypeException('The value given to update() was ' . $type . ' , however the ' . get_class($this) . ' can only store ' . $this->entityClassName . ' instances.', 1249479625);
+        if (!($object instanceof $this->entityClassName)) {
+            throw new IllegalObjectTypeException('The value given to update() was ' . get_class($object) . ' , however the ' . get_class($this) . ' can only store ' . $this->entityClassName . ' instances.', 1249479625);
         }
 
         $this->persistenceManager->update($object);
@@ -209,7 +206,7 @@ public function update($object): void
      *  - countBy<PropertyName>($value, $caseSensitive = true)
      *
      * @param string $method Name of the method
-     * @param array $arguments The arguments
+     * @param array<mixed> $arguments The arguments
      * @return mixed The result of the repository method
      * @api
      */
diff --git a/Neos.Flow/Classes/Persistence/RepositoryInterface.php b/Neos.Flow/Classes/Persistence/RepositoryInterface.php
index 12dcf762dd..23f4e0c6af 100644
--- a/Neos.Flow/Classes/Persistence/RepositoryInterface.php
+++ b/Neos.Flow/Classes/Persistence/RepositoryInterface.php
@@ -93,7 +93,7 @@ public function removeAll(): void;
      *  'bar' => \Neos\Flow\Persistence\QueryInterface::ORDER_DESCENDING
      * )
      *
-     * @param array $defaultOrderings The property names to order by by default
+     * @param array<string,QueryInterface::ORDER_ASCENDING|QueryInterface::ORDER_DESCENDING> $defaultOrderings The property names to order by by default
      * @return void
      * @api
      */
@@ -117,7 +117,7 @@ public function update($object): void;
      *  - countBy<PropertyName>($value, $caseSensitive = true)
      *
      * @param string $method Name of the method
-     * @param array $arguments The arguments
+     * @param array<mixed> $arguments The arguments
      * @return mixed The result of the repository method
      * @api
      */
diff --git a/Neos.Flow/Classes/Property/PropertyMapper.php b/Neos.Flow/Classes/Property/PropertyMapper.php
index 8344fc0d59..516bee0e21 100644
--- a/Neos.Flow/Classes/Property/PropertyMapper.php
+++ b/Neos.Flow/Classes/Property/PropertyMapper.php
@@ -53,7 +53,7 @@ class PropertyMapper
      * 3. Dimension: Priority
      * Value: Type Converter instance
      *
-     * @var array
+     * @var array<string,array<string,array<int,class-string<TypeConverterInterface>>>>
      */
     protected $typeConverters = [];
 
@@ -85,7 +85,7 @@ public function initializeObject()
      * Returns all class names implementing the TypeConverterInterface.
      *
      * @param ObjectManagerInterface $objectManager
-     * @return array Array of type converter implementations
+     * @return array<class-string<TypeConverterInterface>> Array of type converter implementations
      * @Flow\CompileStatic
      */
     public static function getTypeConverterImplementationClassNames($objectManager)
@@ -123,9 +123,10 @@ public function convert($source, $targetType, ?PropertyMappingConfigurationInter
             }
 
             return $result;
-        } catch (SecurityException $exception) {
+        } catch (SecurityException $exception) { /** @phpstan-ignore catch.neverThrown (AOP I guess) */
             throw $exception;
         } catch (\Exception $exception) {
+            /** @phpstan-ignore greater.alwaysFalse (Not sure about this tbh) */
             throw new PropertyException('Could not convert target type "' . $targetType . '"' . (count($currentPropertyPath) > 0 ? ', at property path "' . implode('.', $currentPropertyPath) . '"' : '') . ': ' . $exception->getMessage(), 1297759968, $exception);
         }
     }
@@ -147,7 +148,7 @@ public function getMessages()
      * @param mixed $source the source data to map. MUST be a simple type, NO object allowed!
      * @param string $targetType The type of the target; can be either a class name or a simple type.
      * @param PropertyMappingConfigurationInterface $configuration Configuration for the property mapping.
-     * @param array $currentPropertyPath The property path currently being mapped; used for knowing the context in case an exception is thrown.
+     * @param array<int,string> $currentPropertyPath The property path currently being mapped; used for knowing the context in case an exception is thrown.
      * @return mixed an instance of $targetType
      * @throws Exception\TypeConverterException
      * @throws Exception\InvalidPropertyMappingConfigurationException
@@ -175,10 +176,6 @@ protected function doMapping($source, $targetType, PropertyMappingConfigurationI
         $typeConverter = $this->findTypeConverter($source, $targetType, $configuration);
         $targetType = $typeConverter->getTargetTypeForSource($source, $targetType, $configuration);
 
-        if (!is_object($typeConverter) || !($typeConverter instanceof TypeConverterInterface)) {
-            throw new Exception\TypeConverterException('Type converter for "' . $source . '" -> "' . $targetType . '" not found.');
-        }
-
         $convertedChildProperties = [];
         foreach ($typeConverter->getSourceChildPropertiesToBeConverted($source) as $sourcePropertyName => $sourcePropertyValue) {
             $targetPropertyName = $configuration->getTargetPropertyName($sourcePropertyName);
@@ -232,9 +229,6 @@ protected function findTypeConverter($source, $targetType, PropertyMappingConfig
             return $configuration->getTypeConverter();
         }
 
-        if (!is_string($targetType)) {
-            throw new Exception\InvalidTargetException('The target type was no string, but of type "' . gettype($targetType) . '"', 1297941727);
-        }
         $normalizedTargetType = TypeHandling::normalizeType($targetType);
         $truncatedTargetType = TypeHandling::truncateElementType($normalizedTargetType);
         $converter = null;
@@ -296,7 +290,7 @@ protected function findFirstEligibleTypeConverterInObjectHierarchy($source, $sou
             }
         }
 
-        $converters = $this->getConvertersForInterfaces($convertersForSource, class_implements($targetClass));
+        $converters = $this->getConvertersForInterfaces($convertersForSource, class_implements($targetClass) ?: []);
         $converter = $this->findEligibleConverterWithHighestPriority($converters, $source, $targetType);
 
         if ($converter !== null) {
@@ -341,9 +335,9 @@ protected function findEligibleConverterWithHighestPriority($converters, $source
     }
 
     /**
-     * @param array $convertersForSource
-     * @param array $interfaceNames
-     * @return array
+     * @param array<string,array<int,class-string<TypeConverterInterface>>> $convertersForSource
+     * @param array<class-string> $interfaceNames
+     * @return array<int,class-string<TypeConverterInterface>>
      * @throws DuplicateTypeConverterException
      */
     protected function getConvertersForInterfaces(array $convertersForSource, array $interfaceNames)
@@ -353,7 +347,7 @@ protected function getConvertersForInterfaces(array $convertersForSource, array
             if (isset($convertersForSource[$implementedInterface])) {
                 foreach ($convertersForSource[$implementedInterface] as $priority => $converter) {
                     if (isset($convertersForInterface[$priority])) {
-                        throw new DuplicateTypeConverterException('There exist at least two converters which handle the conversion to an interface with priority "' . $priority . '". ' . get_class($convertersForInterface[$priority]) . ' and ' . get_class($converter), 1297951338);
+                        throw new DuplicateTypeConverterException('There exist at least two converters which handle the conversion to an interface with priority "' . $priority . '". ' . $convertersForInterface[$priority] . ' and ' . $converter, 1297951338);
                     }
                     $convertersForInterface[$priority] = $converter;
                 }
@@ -367,7 +361,7 @@ protected function getConvertersForInterfaces(array $convertersForSource, array
      * Determine the type of the source data, or throw an exception if source was an unsupported format.
      *
      * @param mixed $source
-     * @return array Possible source types (single value for simple typed source, multiple values for object source)
+     * @return array<string> Possible source types (single value for simple typed source, multiple values for object source)
      * @throws Exception\InvalidSourceException
      */
     protected function determineSourceTypes($source)
@@ -396,7 +390,7 @@ protected function determineSourceTypes($source)
     /**
      * Collects all TypeConverter implementations in a multi-dimensional array with source and target types.
      *
-     * @return array
+     * @return array<string,array<string,array<int,class-string<TypeConverterInterface>>>>
      * @throws Exception\DuplicateTypeConverterException
      * @see getTypeConverters
      */
@@ -405,7 +399,6 @@ protected function prepareTypeConverterMap()
         $typeConverterMap = [];
         $typeConverterClassNames = static::getTypeConverterImplementationClassNames($this->objectManager);
         foreach ($typeConverterClassNames as $typeConverterClassName) {
-            /** @var TypeConverterInterface $typeConverter */
             $typeConverter = $this->objectManager->get($typeConverterClassName);
             foreach ($typeConverter->getSupportedSourceTypes() as $supportedSourceType) {
                 $normalizedSourceType = TypeHandling::normalizeType($supportedSourceType);
@@ -430,7 +423,7 @@ protected function prepareTypeConverterMap()
      * 3. Dimension: Priority
      * Value: Type Converter instance
      *
-     * @return array
+     * @return array<string,array<string,array<int,class-string<TypeConverterInterface>>>>
      */
     public function getTypeConverters()
     {
diff --git a/Neos.Flow/Classes/Property/PropertyMappingConfiguration.php b/Neos.Flow/Classes/Property/PropertyMappingConfiguration.php
index dc6021c1cb..c92713b00f 100644
--- a/Neos.Flow/Classes/Property/PropertyMappingConfiguration.php
+++ b/Neos.Flow/Classes/Property/PropertyMappingConfiguration.php
@@ -30,21 +30,21 @@ class PropertyMappingConfiguration implements PropertyMappingConfigurationInterf
      * 2. Dimension: Configuration Key
      * Value: Configuration Value
      *
-     * @var array
+     * @var array<class-string<TypeConverterInterface>,array<int|string,mixed>>
      */
     protected $configuration;
 
     /**
      * Stores the configuration for specific child properties.
      *
-     * @var array<PropertyMappingConfiguration>
+     * @var array<string,PropertyMappingConfiguration>
      */
     protected $subConfigurationForProperty = [];
 
     /**
      * Keys which should be renamed
      *
-     * @var array
+     * @var array<string,string>
      */
     protected $mapping = [];
 
@@ -56,21 +56,21 @@ class PropertyMappingConfiguration implements PropertyMappingConfigurationInterf
     /**
      * List of allowed property names to be converted
      *
-     * @var array
+     * @var array<string,string>
      */
     protected $propertiesToBeMapped = [];
 
     /**
      * List of property names to be skipped during property mapping
      *
-     * @var array
+     * @var array<string,string>
      */
     protected $propertiesToSkip = [];
 
     /**
      * List of disallowed property names which will be ignored while property mapping
      *
-     * @var array
+     * @var array<string,string>
      */
     protected $propertiesNotToBeMapped = [];
 
@@ -260,7 +260,7 @@ public function getTargetPropertyName($sourcePropertyName)
 
     /**
      * @param string $typeConverterClassName
-     * @param string $key
+     * @param string|int $key
      * @return mixed configuration value for the specific $typeConverterClassName. Can be used by Type Converters to fetch converter-specific configuration.
      * @api
      */
@@ -290,8 +290,8 @@ public function setMapping($sourcePropertyName, $targetPropertyName)
     /**
      * Set all options for the given $typeConverter.
      *
-     * @param string $typeConverter class name of type converter
-     * @param array $options
+     * @param class-string<TypeConverterInterface> $typeConverter class name of type converter
+     * @param array<mixed> $options
      * @return PropertyMappingConfiguration this
      * @api
      */
@@ -306,7 +306,7 @@ public function setTypeConverterOptions($typeConverter, array $options)
     /**
      * Set a single option (denoted by $optionKey) for the given $typeConverter.
      *
-     * @param string $typeConverter class name of type converter
+     * @param class-string<TypeConverterInterface> $typeConverter class name of type converter
      * @param int|string $optionKey
      * @param mixed $optionValue
      * @return PropertyMappingConfiguration this
@@ -326,13 +326,18 @@ public function setTypeConverterOption($typeConverter, $optionKey, $optionValue)
      * When setting an option on a subclassed type converter, this option must also be set on
      * all its parent type converters.
      *
-     * @param string $typeConverter The type converter class
-     * @return array Class names of type converters
+     * @param class-string<TypeConverterInterface> $typeConverter The type converter class
+     * @return array<int|string,class-string<TypeConverterInterface>> Class names of type converters
      */
     protected function getTypeConvertersWithParentClasses($typeConverter)
     {
         $typeConverterClasses = class_parents($typeConverter);
-        $typeConverterClasses = $typeConverterClasses === false ? [] : $typeConverterClasses;
+        $typeConverterClasses = $typeConverterClasses === false
+            ? []
+            : array_filter(
+                $typeConverterClasses,
+                fn (string $parentClassName): bool => is_subclass_of($parentClassName, TypeConverterInterface::class)
+            );
         $typeConverterClasses[] = $typeConverter;
         return $typeConverterClasses;
     }
@@ -355,7 +360,7 @@ public function forProperty($propertyPath)
     /**
      * Traverse the property configuration. Only used by forProperty().
      *
-     * @param array $splittedPropertyPath
+     * @param array<string> $splittedPropertyPath
      * @return PropertyMappingConfiguration (or a subclass thereof)
      */
     public function traverseProperties(array $splittedPropertyPath)
diff --git a/Neos.Flow/Classes/Property/PropertyMappingConfigurationInterface.php b/Neos.Flow/Classes/Property/PropertyMappingConfigurationInterface.php
index 786e08b003..55622e78c7 100644
--- a/Neos.Flow/Classes/Property/PropertyMappingConfigurationInterface.php
+++ b/Neos.Flow/Classes/Property/PropertyMappingConfigurationInterface.php
@@ -70,7 +70,7 @@ public function getTargetPropertyName($sourcePropertyName);
 
     /**
      * @param string $typeConverterClassName
-     * @param string $key
+     * @param string|int $key
      * @return mixed configuration value for the specific $typeConverterClassName. Can be used by Type Converters to fetch converter-specific configuration
      * @api
      */
diff --git a/Neos.Flow/Classes/Property/TypeConverter/ArrayConverter.php b/Neos.Flow/Classes/Property/TypeConverter/ArrayConverter.php
index ca088c34cb..216f8b2bc8 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/ArrayConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/ArrayConverter.php
@@ -112,9 +112,9 @@ class ArrayConverter extends AbstractTypeConverter
      *
      * @param mixed $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
-     * @return array
+     * @return array<mixed>
      * @throws InvalidPropertyMappingConfigurationException
      * @throws InvalidSourceException
      * @throws TypeConverterException
@@ -146,9 +146,13 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
             $exportType = $this->getResourceExportType($configuration);
             switch ($exportType) {
                 case self::RESOURCE_EXPORT_TYPE_BASE64:
+                    $fileContent = file_get_contents('resource://' . $source->getSha1());
+                    if ($fileContent === false) {
+                        throw new \Exception('Failed to fetch content for resource ' . $source->getSha1(), 1744060115);
+                    }
                     return [
                         'filename' => $source->getFilename(),
-                        'data' => base64_encode(file_get_contents('resource://' . $source->getSha1())),
+                        'data' => base64_encode($fileContent),
                         'collectionName' => $source->getCollectionName(),
                         'relativePublicationPath' => $source->getRelativePublicationPath(),
                         'mediaType' => $source->getMediaType(),
@@ -159,7 +163,13 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
                     if ($sourceStream === false) {
                         throw new InvalidSourceException(sprintf('Could not get stream of resource "%s" (%s). This might be caused by a broken resource object and can be fixed by running the "resource:clean" command.', $source->getFilename(), $source->getSha1()), 1435842312);
                     }
+                    if (!$configuration) {
+                        throw new \Exception('Cannot resolve target path without a property mapping configuration', 1744060031);
+                    }
                     $targetStream = fopen($configuration->getConfigurationValue(ArrayConverter::class, self::CONFIGURATION_RESOURCE_SAVE_PATH) . '/' . $source->getSha1(), 'w');
+                    if ($targetStream === false) {
+                        throw new \Exception('Could not open target stream', 1744060053);
+                    }
                     stream_copy_to_stream($sourceStream, $targetStream);
                     fclose($targetStream);
                     fclose($sourceStream);
@@ -181,7 +191,7 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
 
     /**
      * @param PropertyMappingConfigurationInterface|null $configuration
-     * @return string
+     * @return non-empty-string
      * @throws InvalidPropertyMappingConfigurationException
      */
     protected function getStringDelimiter(?PropertyMappingConfigurationInterface $configuration = null)
@@ -195,6 +205,8 @@ protected function getStringDelimiter(?PropertyMappingConfigurationInterface $co
             return self::DEFAULT_STRING_DELIMITER;
         } elseif (!is_string($stringDelimiter)) {
             throw new InvalidPropertyMappingConfigurationException(sprintf('CONFIGURATION_STRING_DELIMITER must be of type string, "%s" given', (is_object($stringDelimiter) ? get_class($stringDelimiter) : gettype($stringDelimiter))), 1368433339);
+        } elseif ($stringDelimiter === '') {
+            throw new InvalidPropertyMappingConfigurationException('CONFIGURATION_STRING_DELIMITER must not be empty', 1744060278);
         }
 
         return $stringDelimiter;
diff --git a/Neos.Flow/Classes/Property/TypeConverter/ArrayFromObjectConverter.php b/Neos.Flow/Classes/Property/TypeConverter/ArrayFromObjectConverter.php
index 0c5d63e1d6..772798dbac 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/ArrayFromObjectConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/ArrayFromObjectConverter.php
@@ -50,7 +50,7 @@ class ArrayFromObjectConverter extends AbstractTypeConverter
      * Convert all properties in the source array
      *
      * @param mixed $source
-     * @return array
+     * @return array<string,mixed>
      */
     public function getSourceChildPropertiesToBeConverted($source)
     {
@@ -90,7 +90,7 @@ public function getTypeOfChildProperty($targetType, $propertyName, PropertyMappi
      *
      * @param mixed $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return mixed|Error the target type, or an error object if a user-error occurred
      * @api
diff --git a/Neos.Flow/Classes/Property/TypeConverter/ArrayObjectConverter.php b/Neos.Flow/Classes/Property/TypeConverter/ArrayObjectConverter.php
index ea519af032..24bfc8c087 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/ArrayObjectConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/ArrayObjectConverter.php
@@ -45,9 +45,9 @@ class ArrayObjectConverter extends AbstractTypeConverter
      *
      * @param mixed $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
-     * @return array
+     * @return array<mixed>
      * @throws InvalidSourceException
      * @api
      */
diff --git a/Neos.Flow/Classes/Property/TypeConverter/BooleanConverter.php b/Neos.Flow/Classes/Property/TypeConverter/BooleanConverter.php
index 460f1b3541..135b17ab15 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/BooleanConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/BooleanConverter.php
@@ -46,7 +46,7 @@ class BooleanConverter extends AbstractTypeConverter
      *
      * @param mixed $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return boolean
      * @api
diff --git a/Neos.Flow/Classes/Property/TypeConverter/CollectionConverter.php b/Neos.Flow/Classes/Property/TypeConverter/CollectionConverter.php
index 91755c7d9a..6226dc8fcf 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/CollectionConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/CollectionConverter.php
@@ -49,9 +49,9 @@ class CollectionConverter extends AbstractTypeConverter
      *
      * @param mixed $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
-     * @return ArrayCollection
+     * @return ArrayCollection<string,mixed>
      * @api
      */
     public function convertFrom($source, $targetType, array $convertedChildProperties = [], ?PropertyMappingConfigurationInterface $configuration = null)
@@ -63,7 +63,7 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
      * Returns the source, if it is an array, otherwise an empty array.
      *
      * @param mixed $source
-     * @return array
+     * @return array<mixed>
      * @api
      */
     public function getSourceChildPropertiesToBeConverted($source)
diff --git a/Neos.Flow/Classes/Property/TypeConverter/DateTimeConverter.php b/Neos.Flow/Classes/Property/TypeConverter/DateTimeConverter.php
index 8a68a92286..339b3dce97 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/DateTimeConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/DateTimeConverter.php
@@ -92,7 +92,7 @@ class DateTimeConverter extends AbstractTypeConverter
     /**
      * If conversion is possible.
      *
-     * @param string|int|array $source
+     * @param string|int|array<mixed> $source
      * @param string $targetType
      * @return boolean
      */
@@ -101,21 +101,16 @@ public function canConvertFrom($source, $targetType)
         if (!is_callable([$targetType, 'createFromFormat'])) {
             return false;
         }
-        if (is_array($source)) {
-            return true;
-        }
-        if (is_integer($source)) {
-            return true;
-        }
-        return is_string($source);
+
+        return true;
     }
 
     /**
      * Converts $source to a \DateTime using the configured dateFormat
      *
-     * @param string|integer|array $source the string to be converted to a \DateTime object
+     * @param string|integer|array<string,mixed> $source the string to be converted to a \DateTime object
      * @param string $targetType must be "DateTime"
-     * @param array $convertedChildProperties not used currently
+     * @param array<string,mixed> $convertedChildProperties not used currently
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return \DateTimeInterface|null|Error
      * @throws InvalidPropertyMappingConfigurationException
@@ -171,7 +166,7 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
         if ($date === false) {
             return new Error('The date "%s" was not recognized (for format "%s").', 1307719788, [$dateAsString, $dateFormat]);
         }
-        if (isset($source['hour'], $source['minute'], $source['second']) && is_array($source)) {
+        if (isset($source['hour'], $source['minute'], $source['second'])) {
             $date = $this->overrideTime($date, $source);
         }
         return $date;
@@ -179,7 +174,7 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
 
     /**
      * Returns whether date information (day, month, year) are present as keys in $source.
-     * @param array $source
+     * @param array<string,mixed> $source
      * @return bool
      */
     protected function isDatePartKeysProvided(array $source)
@@ -215,7 +210,7 @@ protected function getDefaultDateFormat(?PropertyMappingConfigurationInterface $
      * Overrides hour, minute & second of the given date with the values in the $source array
      *
      * @param \DateTimeInterface $date
-     * @param array $source
+     * @param array<string,mixed> $source
      * @return \DateTimeInterface
      */
     protected function overrideTime(\DateTimeInterface $date, array $source)
@@ -223,7 +218,7 @@ protected function overrideTime(\DateTimeInterface $date, array $source)
         $hour = isset($source['hour']) ? (integer)$source['hour'] : 0;
         $minute = isset($source['minute']) ? (integer)$source['minute'] : 0;
         $second = isset($source['second']) ? (integer)$source['second'] : 0;
-        if ($date instanceof \DateTime || $date instanceof \DateTimeImmutable) {
+        if (is_callable([$date, 'setTime'])) {
             $date = $date->setTime($hour, $minute, $second);
         }
         return $date;
diff --git a/Neos.Flow/Classes/Property/TypeConverter/FloatConverter.php b/Neos.Flow/Classes/Property/TypeConverter/FloatConverter.php
index 5cd49c1183..d8919f9e9e 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/FloatConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/FloatConverter.php
@@ -124,7 +124,7 @@ class FloatConverter extends AbstractTypeConverter
      *
      * @param mixed $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return float|Error|null
      * @throws InvalidPropertyMappingConfigurationException
@@ -172,7 +172,7 @@ protected function parseUsingLocaleIfConfigured($source, PropertyMappingConfigur
         }
 
         if (!$locale instanceof Locale) {
-            $exceptionMessage = 'Determined locale is not of type "\Neos\Flow\I18n\Locale", but of type "' . (is_object($locale) ? get_class($locale) : gettype($locale)) . '".';
+            $exceptionMessage = 'Determined locale is not of type "\Neos\Flow\I18n\Locale", but of type "' . gettype($locale) . '".';
             throw new InvalidPropertyMappingConfigurationException($exceptionMessage, 1334837413);
         }
 
@@ -215,8 +215,8 @@ protected function parseUsingLocaleIfConfigured($source, PropertyMappingConfigur
      * Helper method to collect configuration for this class.
      *
      * @param PropertyMappingConfigurationInterface $configuration
-     * @param array $configurationKeys
-     * @return array
+     * @param array<string> $configurationKeys
+     * @return array<string,mixed>
      */
     protected function getConfigurationKeysAndValues(PropertyMappingConfigurationInterface $configuration, array $configurationKeys)
     {
diff --git a/Neos.Flow/Classes/Property/TypeConverter/IntegerConverter.php b/Neos.Flow/Classes/Property/TypeConverter/IntegerConverter.php
index 6ccf96a562..edecebe380 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/IntegerConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/IntegerConverter.php
@@ -47,7 +47,7 @@ class IntegerConverter extends AbstractTypeConverter
      *
      * @param int|string|\DateTimeInterface|null $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return integer|null|Error
      * @api
diff --git a/Neos.Flow/Classes/Property/TypeConverter/MediaTypeConverter.php b/Neos.Flow/Classes/Property/TypeConverter/MediaTypeConverter.php
index f78b1cd663..96d4f58d31 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/MediaTypeConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/MediaTypeConverter.php
@@ -48,9 +48,9 @@ class MediaTypeConverter extends AbstractTypeConverter implements MediaTypeConve
      *
      * @param string $source the raw request body
      * @param string $targetType must be "array"
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
-     * @return array|string|integer Note that this TypeConverter may return a non-array in case of JSON media type, even though he declares to only convert to array
+     * @return array<mixed>|string|integer Note that this TypeConverter may return a non-array in case of JSON media type, even though he declares to only convert to array
      * @api
      */
     public function convertFrom($source, $targetType, array $convertedChildProperties = [], ?PropertyMappingConfigurationInterface $configuration = null)
@@ -71,13 +71,13 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
      *
      * @param string $requestBody the raw request body
      * @param string $mediaType the configured media type (for example "application/json")
-     * @return array|string|integer
+     * @return array<mixed>|string|integer
      * @api
      */
     protected function convertMediaType($requestBody, $mediaType)
     {
         $mediaTypeParts = MediaTypes::parseMediaType($mediaType);
-        if (!isset($mediaTypeParts['subtype']) || $mediaTypeParts['subtype'] === '') {
+        if ($mediaTypeParts['subtype'] === '') {
             return [];
         }
         $result = [];
diff --git a/Neos.Flow/Classes/Property/TypeConverter/ObjectConverter.php b/Neos.Flow/Classes/Property/TypeConverter/ObjectConverter.php
index 62f6599243..29cd9fd4e5 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/ObjectConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/ObjectConverter.php
@@ -79,7 +79,18 @@ class ObjectConverter extends AbstractTypeConverter
     /**
      * As it is very likely that the constructor arguments are needed twice we should cache them for the request.
      *
-     * @var array
+     * @var array<class-string,array<string,array{
+     *       position: int,
+     *       optional: bool,
+     *       type: ?string,
+     *       class: ?string,
+     *       array: bool,
+     *       byReference: bool,
+     *       allowsNull: bool,
+     *       defaultValue: mixed,
+     *       scalarDeclaration: bool,
+     *       annotations: array<string,array<int,object>>,
+     *  }>>
      */
     protected $constructorReflectionFirstLevelCache = [];
 
@@ -116,7 +127,7 @@ public function getSourceChildPropertiesToBeConverted($source)
     /**
      * The type of a property is determined by the reflection service.
      *
-     * @param string $targetType
+     * @param class-string $targetType
      * @param string $propertyName
      * @param PropertyMappingConfigurationInterface $configuration
      * @return string|null
@@ -149,6 +160,9 @@ public function getTypeOfChildProperty($targetType, $propertyName, PropertyMappi
                     // would not find a property mapper. It is needed because the ObjectConverter doesn't use class schemata,
                     // but reads the annotations directly.
                     $declaredType = strtok(trim(current($varTagValues), " \n\t"), " \n\t");
+                    if ($declaredType === false) {
+                        throw new \Exception('Invalid declared type', 1744058940);
+                    }
                     try {
                         $parsedType = TypeHandling::parseType($declaredType);
                     } catch (InvalidTypeException $exception) {
@@ -173,7 +187,7 @@ public function getTypeOfChildProperty($targetType, $propertyName, PropertyMappi
      *
      * @param mixed $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return object the target type
      * @throws InvalidTargetException
@@ -185,6 +199,7 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
         $object = $this->buildObject($convertedChildProperties, $targetType);
         foreach ($convertedChildProperties as $propertyName => $propertyValue) {
             $result = ObjectAccess::setProperty($object, $propertyName, $propertyValue);
+            /** @var object $object */
             if ($result === false) {
                 $exceptionMessage = sprintf(
                     'Property "%s" having a value of type "%s" could not be set in target object of type "%s". Make sure that the property is accessible properly, for example via an appropriate setter method.',
@@ -214,7 +229,7 @@ public function getTargetTypeForSource($source, $originalTargetType, ?PropertyMa
     {
         $targetType = $originalTargetType;
 
-        if (is_array($source) && array_key_exists('__type', $source)) {
+        if (is_array($source) && array_key_exists('__type', $source) && is_string($source['__type'])) {
             $targetType = $source['__type'];
 
             if ($configuration === null) {
@@ -224,6 +239,7 @@ public function getTargetTypeForSource($source, $originalTargetType, ?PropertyMa
                 throw new InvalidPropertyMappingConfigurationException('Override of target type not allowed. To enable this, you need to set the PropertyMappingConfiguration Value "CONFIGURATION_OVERRIDE_TARGET_TYPE_ALLOWED" to true.', 1317050430);
             }
 
+            /** @todo is_a is not recursive! replace with is_subclass_of or similar */
             if ($targetType !== $originalTargetType && is_a($targetType, $originalTargetType, true) === false) {
                 throw new InvalidDataTypeException('The given type "' . $targetType . '" is not a subtype of "' . $originalTargetType . '".', 1317048056);
             }
@@ -239,7 +255,7 @@ public function getTargetTypeForSource($source, $originalTargetType, ?PropertyMa
      *
      * Furthermore, the constructor arguments are removed from $possibleConstructorArgumentValues
      *
-     * @param array &$possibleConstructorArgumentValues
+     * @param array<string,mixed> &$possibleConstructorArgumentValues
      * @param string $objectType
      * @return object The created instance
      * @throws InvalidTargetException if a required constructor argument is missing
@@ -248,6 +264,9 @@ protected function buildObject(array &$possibleConstructorArgumentValues, $objec
     {
         $constructorArguments = [];
         $className = $this->objectManager->getClassNameByObjectName($objectType);
+        if ($className === false) {
+            throw new \Exception('Invalid object type '. $objectType, 1744058576);
+        }
         $constructorSignature = $this->getConstructorArgumentsForClass($className);
         if (count($constructorSignature)) {
             foreach ($constructorSignature as $constructorArgumentName => $constructorArgumentReflection) {
@@ -256,7 +275,7 @@ protected function buildObject(array &$possibleConstructorArgumentValues, $objec
                     unset($possibleConstructorArgumentValues[$constructorArgumentName]);
                 } elseif ($constructorArgumentReflection['optional'] === true) {
                     $constructorArguments[] = $constructorArgumentReflection['defaultValue'];
-                } elseif ($this->objectManager->isRegistered($constructorArgumentReflection['type']) && $this->objectManager->getScope($constructorArgumentReflection['type']) === Configuration::SCOPE_SINGLETON) {
+                } elseif ($constructorArgumentReflection['type'] && $this->objectManager->isRegistered($constructorArgumentReflection['type']) && $this->objectManager->getScope($constructorArgumentReflection['type']) === Configuration::SCOPE_SINGLETON) {
                     $constructorArguments[] = $this->objectManager->get($constructorArgumentReflection['type']);
                 } else {
                     throw new InvalidTargetException('Missing constructor argument "' . $constructorArgumentName . '" for object of type "' . $objectType . '".', 1268734872);
@@ -272,8 +291,19 @@ protected function buildObject(array &$possibleConstructorArgumentValues, $objec
     /**
      * Get the constructor argument reflection for the given object type.
      *
-     * @param string $className
-     * @return array<array>
+     * @param class-string $className
+     * @return array<string,array{
+     *        position: int,
+     *        optional: bool,
+     *        type: ?string,
+     *        class: ?string,
+     *        array: bool,
+     *        byReference: bool,
+     *        allowsNull: bool,
+     *        defaultValue: mixed,
+     *        scalarDeclaration: bool,
+     *        annotations: array<string,array<int,object>>,
+     * }>
      */
     protected function getConstructorArgumentsForClass($className)
     {
diff --git a/Neos.Flow/Classes/Property/TypeConverter/PersistentObjectConverter.php b/Neos.Flow/Classes/Property/TypeConverter/PersistentObjectConverter.php
index 9ce89473ea..028eef44ea 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/PersistentObjectConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/PersistentObjectConverter.php
@@ -114,7 +114,7 @@ public function getSourceChildPropertiesToBeConverted($source)
     /**
      * The type of a property is determined by the reflection service.
      *
-     * @param string $targetType
+     * @param class-string $targetType
      * @param string $propertyName
      * @param PropertyMappingConfigurationInterface $configuration
      * @return string
@@ -128,6 +128,9 @@ public function getTypeOfChildProperty($targetType, $propertyName, PropertyMappi
         }
 
         $schema = $this->reflectionService->getClassSchema($targetType);
+        if (!$schema) {
+            throw new InvalidTargetException('Schema for target object of type "' . $targetType . '" not found.', 1744057928);
+        }
         $setterMethodName = ObjectAccess::buildSetterMethodName($propertyName);
         $constructorParameters = $this->reflectionService->getMethodParameters($targetType, '__construct');
 
@@ -154,7 +157,7 @@ public function getTypeOfChildProperty($targetType, $propertyName, PropertyMappi
      *
      * @param mixed $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface $configuration
      * @return object|TargetNotFoundError|null the converted entity/value object or an instance of TargetNotFoundError if the object could not be resolved
      * @throws \InvalidArgumentException|InvalidTargetException
@@ -191,6 +194,7 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
 
         foreach ($convertedChildProperties as $propertyName => $propertyValue) {
             // We need to check for "immutable" constructor arguments that have no setter and remove them.
+            /** @var object $object */
             if (isset($objectConstructorArguments[$propertyName]) && !ObjectAccess::isPropertySettable($object, $propertyName)) {
                 $currentPropertyValue = ObjectAccess::getProperty($object, $propertyName);
                 if ($currentPropertyValue === $propertyValue) {
@@ -217,15 +221,16 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
             }
         }
 
+        /** @var object $object */
         return $object;
     }
 
     /**
      * Handle the case if $source is an array.
      *
-     * @param array $source
+     * @param array<mixed> $source
      * @param class-string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> &$convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return object|TargetNotFoundError
      * @throws InvalidPropertyMappingConfigurationException
@@ -267,7 +272,7 @@ protected function handleArrayData(array $source, $targetType, array &$converted
      * Set the given $identity on the created $object.
      *
      * @param object $object
-     * @param string|array $identity
+     * @param string|array<mixed> $identity
      * @return void
      * @todo set identity properly if it is composite or custom property
      */
@@ -300,7 +305,7 @@ protected function fetchObjectFromPersistence($identity, $targetType)
     /**
      * Finds an object from the repository by searching for its identity properties.
      *
-     * @param array $identityProperties Property names and values to search for
+     * @param array<string,mixed> $identityProperties Property names and values to search for
      * @param string $type The object type to look for
      * @return object|null Either the object matching the identity or NULL if no object was found
      * @throws DuplicateObjectException if more than one object was found
@@ -311,7 +316,7 @@ protected function findObjectByIdentityProperties(array $identityProperties, $ty
         $classSchema = $this->reflectionService->getClassSchema($type);
 
         $equals = [];
-        foreach ($classSchema->getIdentityProperties() as $propertyName => $propertyType) {
+        foreach ($classSchema?->getIdentityProperties() ?: [] as $propertyName => $propertyType) {
             if (isset($identityProperties[$propertyName])) {
                 if ($propertyType === 'string') {
                     $equals[] = $query->equals($propertyName, $identityProperties[$propertyName], false);
diff --git a/Neos.Flow/Classes/Property/TypeConverter/PersistentObjectSerializer.php b/Neos.Flow/Classes/Property/TypeConverter/PersistentObjectSerializer.php
index 5231260403..0ee57cbfde 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/PersistentObjectSerializer.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/PersistentObjectSerializer.php
@@ -52,7 +52,7 @@ class PersistentObjectSerializer extends AbstractTypeConverter
      *
      * @param object $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return mixed The identifier for the object if it is known, or NULL
      */
diff --git a/Neos.Flow/Classes/Property/TypeConverter/ScalarTypeToObjectConverter.php b/Neos.Flow/Classes/Property/TypeConverter/ScalarTypeToObjectConverter.php
index 988e0a5ad4..4656aa035f 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/ScalarTypeToObjectConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/ScalarTypeToObjectConverter.php
@@ -58,6 +58,9 @@ class ScalarTypeToObjectConverter extends AbstractTypeConverter
      */
     public function canConvertFrom($source, $targetType)
     {
+        if (!class_exists($targetType)) {
+            return false;
+        }
         if ((
             $this->reflectionService->isClassAnnotatedWith($targetType, Flow\Entity::class) ||
             $this->reflectionService->isClassAnnotatedWith($targetType, Flow\ValueObject::class) ||
@@ -71,7 +74,8 @@ public function canConvertFrom($source, $targetType)
             return false;
         }
         $methodParameter = array_shift($methodParameters);
-        return TypeHandling::normalizeType($methodParameter['type']) === TypeHandling::normalizeType(gettype($source));
+        $methodParameterType = $methodParameter['type'] ?? null;
+        return ($methodParameterType ? TypeHandling::normalizeType($methodParameterType) : null) === TypeHandling::normalizeType(gettype($source));
     }
 
     /**
@@ -79,7 +83,7 @@ public function canConvertFrom($source, $targetType)
      *
      * @param string|float|integer|bool $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return object
      */
diff --git a/Neos.Flow/Classes/Property/TypeConverter/SessionConverter.php b/Neos.Flow/Classes/Property/TypeConverter/SessionConverter.php
index 3729434ed9..72ab19178b 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/SessionConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/SessionConverter.php
@@ -14,6 +14,7 @@
 use Neos\Flow\Annotations as Flow;
 use Neos\Flow\Property\PropertyMappingConfigurationInterface;
 use Neos\Flow\Session\Session;
+use Neos\Flow\Session\SessionInterface;
 use Neos\Flow\Session\SessionManagerInterface;
 
 /**
@@ -70,9 +71,9 @@ public function canConvertFrom($source, $targetType)
      *
      * @param string $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
-     * @return object the target type
+     * @return ?SessionInterface the target type
      */
     public function convertFrom($source, $targetType, array $convertedChildProperties = [], ?PropertyMappingConfigurationInterface $configuration = null)
     {
diff --git a/Neos.Flow/Classes/Property/TypeConverter/StringConverter.php b/Neos.Flow/Classes/Property/TypeConverter/StringConverter.php
index dce5764954..ee58bc43ab 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/StringConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/StringConverter.php
@@ -94,7 +94,7 @@ class StringConverter extends AbstractTypeConverter
      *
      * @param mixed $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return string
      * @throws InvalidPropertyMappingConfigurationException
@@ -113,7 +113,7 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
                 case self::ARRAY_FORMAT_CSV:
                     return implode($this->getCsvDelimiter($configuration), $source);
                 case self::ARRAY_FORMAT_JSON:
-                    return json_encode($source);
+                    return json_encode($source, JSON_THROW_ON_ERROR);
                 default:
                     throw new InvalidPropertyMappingConfigurationException(sprintf('Invalid array export format "%s" given', $this->getArrayFormat($configuration)), 1404317220);
             }
diff --git a/Neos.Flow/Classes/Property/TypeConverter/TypedArrayConverter.php b/Neos.Flow/Classes/Property/TypeConverter/TypedArrayConverter.php
index f183ca93cf..5550c4b281 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/TypedArrayConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/TypedArrayConverter.php
@@ -56,11 +56,11 @@ public function canConvertFrom($source, $targetType)
     }
 
     /**
-     * @param array $source An array of objects/simple types
+     * @param array<mixed> $source An array of objects/simple types
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
-     * @return array
+     * @return array<string,mixed>
      * @api
      */
     public function convertFrom($source, $targetType, array $convertedChildProperties = [], ?PropertyMappingConfigurationInterface $configuration = null)
@@ -72,7 +72,7 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
      * Returns the source, if it is an array, otherwise an empty array.
      *
      * @param mixed $source
-     * @return array
+     * @return array<mixed>
      */
     public function getSourceChildPropertiesToBeConverted($source)
     {
@@ -85,7 +85,7 @@ public function getSourceChildPropertiesToBeConverted($source)
      * @param string $targetType
      * @param string $propertyName
      * @param PropertyMappingConfigurationInterface $configuration
-     * @return string
+     * @return ?string
      */
     public function getTypeOfChildProperty($targetType, $propertyName, PropertyMappingConfigurationInterface $configuration)
     {
diff --git a/Neos.Flow/Classes/Property/TypeConverter/UriTypeConverter.php b/Neos.Flow/Classes/Property/TypeConverter/UriTypeConverter.php
index f8556886df..3a6299e3c2 100644
--- a/Neos.Flow/Classes/Property/TypeConverter/UriTypeConverter.php
+++ b/Neos.Flow/Classes/Property/TypeConverter/UriTypeConverter.php
@@ -46,7 +46,7 @@ class UriTypeConverter extends AbstractTypeConverter
      *
      * @param string $source The URI to be converted
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return Uri|Error if the input format is not supported or could not be converted for other reasons
      */
diff --git a/Neos.Flow/Classes/Property/TypeConverterInterface.php b/Neos.Flow/Classes/Property/TypeConverterInterface.php
index d9bb5bbc8e..47c0e0b561 100644
--- a/Neos.Flow/Classes/Property/TypeConverterInterface.php
+++ b/Neos.Flow/Classes/Property/TypeConverterInterface.php
@@ -104,7 +104,7 @@ public function getTypeOfChildProperty($targetType, $propertyName, PropertyMappi
      *
      * @param mixed $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<string,mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return mixed|Error the target type, or an error object if a user-error occurred
      * @throws Exception\TypeConverterException thrown in case a developer error occurred
diff --git a/Neos.Flow/Classes/Reflection/ClassReflection.php b/Neos.Flow/Classes/Reflection/ClassReflection.php
index 34664fab6c..6ecc334ca4 100644
--- a/Neos.Flow/Classes/Reflection/ClassReflection.php
+++ b/Neos.Flow/Classes/Reflection/ClassReflection.php
@@ -16,6 +16,7 @@
 /**
  * Extended version of the ReflectionClass
  *
+ * @extends \ReflectionClass<object>
  * @Flow\Proxy(false)
  */
 class ClassReflection extends \ReflectionClass
@@ -39,7 +40,7 @@ static function ($className) use ($classNameOrObject) {
     }
 
     /**
-     * @var DocCommentParser Holds an instance of the doc comment parser for this class
+     * @var ?DocCommentParser Holds an instance of the doc comment parser for this class
      */
     protected $docCommentParser;
 
@@ -48,12 +49,14 @@ static function ($className) use ($classNameOrObject) {
      * that MethodReflection objects are returned instead of the
      * original ReflectionMethod instances.
      *
-     * @return MethodReflection Method reflection object of the constructor method
+     * @return ?MethodReflection Method reflection object of the constructor method
      */
-    public function getConstructor(): MethodReflection
+    public function getConstructor(): ?MethodReflection
     {
         $parentConstructor = parent::getConstructor();
-        return (!is_object($parentConstructor)) ? $parentConstructor : new MethodReflection($this->getName(), $parentConstructor->getName());
+        return $parentConstructor === null
+            ? $parentConstructor
+            : new MethodReflection($this->getName(), $parentConstructor->getName());
     }
 
     /**
@@ -165,7 +168,7 @@ public function isTaggedWith($tag)
     /**
      * Returns an array of tags and their values
      *
-     * @return array Tags and values
+     * @return array<string,array<int,string>> Tags and values
      */
     public function getTagsValues()
     {
@@ -175,7 +178,7 @@ public function getTagsValues()
     /**
      * Returns the values of the specified tag
      * @param string $tag
-     * @return array Values of the given tag
+     * @return array<int,string> Values of the given tag
      */
     public function getTagValues($tag)
     {
@@ -205,7 +208,7 @@ public function newInstanceWithoutConstructor(): object
     {
         $instance = parent::newInstanceWithoutConstructor();
 
-        if (method_exists($instance, '__wakeup') && is_callable([$instance, '__wakeup'])) {
+        if (method_exists($instance, '__wakeup')) {
             $instance->__wakeup();
         }
 
@@ -221,8 +224,11 @@ public function newInstanceWithoutConstructor(): object
     protected function getDocCommentParser()
     {
         if (!is_object($this->docCommentParser)) {
-            $this->docCommentParser = new DocCommentParser;
-            $this->docCommentParser->parseDocComment($this->getDocComment());
+            $this->docCommentParser = new DocCommentParser();
+            $docComment = $this->getDocComment();
+            if ($docComment) {
+                $this->docCommentParser->parseDocComment($docComment);
+            }
         }
         return $this->docCommentParser;
     }
diff --git a/Neos.Flow/Classes/Reflection/ClassSchema.php b/Neos.Flow/Classes/Reflection/ClassSchema.php
index df24913f7a..98bd7312aa 100644
--- a/Neos.Flow/Classes/Reflection/ClassSchema.php
+++ b/Neos.Flow/Classes/Reflection/ClassSchema.php
@@ -11,6 +11,7 @@
  * source code.
  */
 
+use Neos\Flow\Persistence\RepositoryInterface;
 use Neos\Utility\Exception\InvalidTypeException;
 use Neos\Utility\TypeHandling;
 
@@ -47,21 +48,27 @@ class ClassSchema
     protected $lazyLoadable = false;
 
     /**
-     * @var string|null
+     * @var class-string<RepositoryInterface>|null
      */
     protected $repositoryClassName;
 
     /**
      * Properties of the class which need to be persisted
      *
-     * @var array
+     * @var array<string,array{
+     *     type: string,
+     *     elementType: ?string,
+     *     nullable: bool,
+     *     lazy: bool,
+     *     transient: bool,
+     * }>
      */
     protected $properties = [];
 
     /**
      * The properties forming the identity of an object
      *
-     * @var array
+     * @var array<string,string>
      */
     protected $identityProperties = [];
 
@@ -137,7 +144,13 @@ public function addProperty($name, $type, $lazy = false, $transient = false)
      * hasProperty($propertyName) before!
      *
      * @param string $propertyName
-     * @return array
+     * @return array{
+     *       type: string,
+     *       elementType: ?string,
+     *       nullable: bool,
+     *       lazy: bool,
+     *       transient: bool,
+     * }
      */
     public function getProperty($propertyName)
     {
@@ -147,7 +160,13 @@ public function getProperty($propertyName)
     /**
      * Returns all properties defined in this schema
      *
-     * @return array
+     * @return array<string,array{
+     *      type: string,
+     *      elementType: ?string,
+     *      nullable: bool,
+     *      lazy: bool,
+     *      transient: bool,
+     * }>
      */
     public function getProperties()
     {
@@ -198,7 +217,7 @@ public function getModelType()
     /**
      * Set the class name of the repository managing an entity.
      *
-     * @param string $repositoryClassName
+     * @param ?class-string<RepositoryInterface> $repositoryClassName
      * @return void
      * @throws Exception\ClassSchemaConstraintViolationException
      */
@@ -211,7 +230,7 @@ public function setRepositoryClassName($repositoryClassName)
     }
 
     /**
-     * @return string
+     * @return ?class-string<RepositoryInterface>
      */
     public function getRepositoryClassName()
     {
@@ -300,7 +319,7 @@ public function markAsIdentityProperty($propertyName)
     /**
      * Gets the properties (names and types) forming the identity of an object.
      *
-     * @return array
+     * @return array<string,string>
      * @see markAsIdentityProperty()
      */
     public function getIdentityProperties()
diff --git a/Neos.Flow/Classes/Reflection/DocCommentParser.php b/Neos.Flow/Classes/Reflection/DocCommentParser.php
index 514a976456..3eca9e1db4 100644
--- a/Neos.Flow/Classes/Reflection/DocCommentParser.php
+++ b/Neos.Flow/Classes/Reflection/DocCommentParser.php
@@ -28,7 +28,7 @@ class DocCommentParser
 
     /**
      * An array of tag names and their values (multiple values are possible)
-     * @var array
+     * @var array<string,array<int,string>>
      */
     protected $tags = [];
 
@@ -47,9 +47,9 @@ public function parseDocComment($docComment)
 
         $lines = explode(chr(10), $docComment);
         foreach ($lines as $line) {
-            $line = trim(preg_replace('/\*\/$/', '', $line));
+            $line = trim(preg_replace('/\*\/$/', '', $line) ?: '');
             if ($line !== '' && strpos($line, '* @') !== false) {
-                $this->parseTag(substr($line, strpos($line, '@')));
+                $this->parseTag(substr($line, strpos($line, '@') ?: 0));
             } elseif (count($this->tags) === 0) {
                 $this->description .= preg_replace('/\s*\\/?[\\\\*]*\s?(.*)$/', '$1', $line) . chr(10);
             }
@@ -60,7 +60,7 @@ public function parseDocComment($docComment)
     /**
      * Returns the tags which have been previously parsed
      *
-     * @return array Array of tag names and their (multiple) values
+     * @return array<string,array<int,string>> Array of tag names and their (multiple) values
      */
     public function getTagsValues()
     {
@@ -73,7 +73,7 @@ public function getTagsValues()
      * available.
      *
      * @param string $tagName The tag name to retrieve the values for
-     * @return array The tag's values
+     * @return array<int,string> The tag's values
      * @throws Exception
      */
     public function getTagValues($tagName)
@@ -116,7 +116,7 @@ protected function parseTag($line)
     {
         $tagAndValue = [];
         if (preg_match('/@[A-Za-z0-9\\\\]+\\\\([A-Za-z0-9]+)(?:\\((.*)\\))?$/', $line, $tagAndValue) === 0) {
-            $tagAndValue = preg_split('/\s/', $line, 2);
+            $tagAndValue = preg_split('/\s/', $line, 2) ?: [];
         } else {
             array_shift($tagAndValue);
         }
diff --git a/Neos.Flow/Classes/Reflection/MethodReflection.php b/Neos.Flow/Classes/Reflection/MethodReflection.php
index b5e8a0e1e7..37b4317881 100644
--- a/Neos.Flow/Classes/Reflection/MethodReflection.php
+++ b/Neos.Flow/Classes/Reflection/MethodReflection.php
@@ -21,7 +21,7 @@
 class MethodReflection extends \ReflectionMethod
 {
     /**
-     * @var DocCommentParser An instance of the doc comment parser
+     * @var ?DocCommentParser An instance of the doc comment parser
      */
     protected $docCommentParser;
 
@@ -66,7 +66,7 @@ public function isTaggedWith($tag)
     /**
      * Returns an array of tags and their values
      *
-     * @return array Tags and values
+     * @return array<string,array<int,string>> Tags and values
      */
     public function getTagsValues()
     {
@@ -77,7 +77,7 @@ public function getTagsValues()
      * Returns the values of the specified tag
      *
      * @param string $tag Tag name to check for
-     * @return array Values of the given tag
+     * @return array<int,string> Values of the given tag
      */
     public function getTagValues($tag)
     {
@@ -99,9 +99,6 @@ public function getDescription()
      */
     public function getDeclaredReturnType()
     {
-        if (!is_callable([$this, 'getReturnType'])) {
-            return null;
-        }
         $type = $this->getReturnType();
         return $type !== null ? ltrim((string)$type, '?') : null;
     }
@@ -111,9 +108,6 @@ public function getDeclaredReturnType()
      */
     public function isDeclaredReturnTypeNullable()
     {
-        if (!is_callable([$this, 'getReturnType'])) {
-            return false;
-        }
         $type = $this->getReturnType();
         return $type !== null && $type->allowsNull();
     }
@@ -127,8 +121,11 @@ public function isDeclaredReturnTypeNullable()
     protected function getDocCommentParser()
     {
         if (!is_object($this->docCommentParser)) {
-            $this->docCommentParser = new DocCommentParser;
-            $this->docCommentParser->parseDocComment($this->getDocComment());
+            $this->docCommentParser = new DocCommentParser();
+            $docComment = $this->getDocComment();
+            if ($docComment) {
+                $this->docCommentParser->parseDocComment($docComment);
+            }
         }
         return $this->docCommentParser;
     }
diff --git a/Neos.Flow/Classes/Reflection/ParameterReflection.php b/Neos.Flow/Classes/Reflection/ParameterReflection.php
index 94c560aac0..11d4831436 100644
--- a/Neos.Flow/Classes/Reflection/ParameterReflection.php
+++ b/Neos.Flow/Classes/Reflection/ParameterReflection.php
@@ -28,11 +28,12 @@ class ParameterReflection extends \ReflectionParameter
     /**
      * Returns the declaring class
      *
-     * @return ClassReflection The declaring class
+     * @return ?ClassReflection The declaring class
      */
-    public function getDeclaringClass(): ClassReflection
+    public function getDeclaringClass(): ?ClassReflection
     {
-        return new ClassReflection(parent::getDeclaringClass()->getName());
+        $reflectionClass = parent::getDeclaringClass();
+        return $reflectionClass ? new ClassReflection($reflectionClass->getName()) : null;
     }
 
     /**
diff --git a/Neos.Flow/Classes/Reflection/PropertyReflection.php b/Neos.Flow/Classes/Reflection/PropertyReflection.php
index 1b59ba4c4e..4afc83c6f8 100644
--- a/Neos.Flow/Classes/Reflection/PropertyReflection.php
+++ b/Neos.Flow/Classes/Reflection/PropertyReflection.php
@@ -21,7 +21,7 @@
 class PropertyReflection extends \ReflectionProperty
 {
     /**
-     * @var DocCommentParser An instance of the doc comment parser
+     * @var ?DocCommentParser An instance of the doc comment parser
      */
     protected $docCommentParser;
 
@@ -58,7 +58,7 @@ public function getDeclaringClass(): ClassReflection
     /**
      * Returns an array of tags and their values
      *
-     * @return array Tags and values
+     * @return array<string,array<int,string>> Tags and values
      */
     public function getTagsValues()
     {
@@ -69,7 +69,7 @@ public function getTagsValues()
      * Returns the values of the specified tag
      *
      * @param string $tag
-     * @return array Values of the given tag
+     * @return array<int,string> Values of the given tag
      */
     public function getTagValues($tag)
     {
@@ -137,8 +137,11 @@ public function setValue($object = null, $value = null): void
     protected function getDocCommentParser()
     {
         if (!is_object($this->docCommentParser)) {
-            $this->docCommentParser = new DocCommentParser;
-            $this->docCommentParser->parseDocComment($this->getDocComment());
+            $this->docCommentParser = new DocCommentParser();
+            $docComment = $this->getDocComment();
+            if ($docComment) {
+                $this->docCommentParser->parseDocComment($docComment);
+            }
         }
         return $this->docCommentParser;
     }
diff --git a/Neos.Flow/Classes/Reflection/ReflectionService.php b/Neos.Flow/Classes/Reflection/ReflectionService.php
index 5c720b5db0..e2281a39c1 100644
--- a/Neos.Flow/Classes/Reflection/ReflectionService.php
+++ b/Neos.Flow/Classes/Reflection/ReflectionService.php
@@ -92,6 +92,9 @@ class ReflectionService
     protected const DATA_PARAMETER_ANNOTATIONS = 25;
 
     protected Reader $annotationReader;
+    /**
+     * @var array<string,array<class-string>> class names per package (key)
+     */
     protected array $availableClassNames = [];
     protected VariableFrontend $reflectionDataRuntimeCache;
     protected VariableFrontend $classSchemataRuntimeCache;
@@ -107,40 +110,87 @@ class ReflectionService
     /**
      * a cache which stores the use statements reflected for a particular class
      * (only relevant for un-expanded "var" and "param" annotations)
+     *
+     * @var array<class-string,array<string>>
      */
     protected array $useStatementsForClassCache;
 
+    /**
+     * @var array<string,mixed>
+     */
     protected array $settings = [];
 
     /**
      * Array of annotation classnames and the names of classes which are annotated with them
+     *
+     * @var array<class-string,array<class-string, bool>>
      */
     protected array $annotatedClasses = [];
 
     /**
      * Array of method annotations and the classes and methods which are annotated with them
+     *
+     * @var array<class-string,array<class-string,array<string,string>>>
      */
     protected array $classesByMethodAnnotations = [];
 
     /**
      * Schemata of all classes which can be persisted
      *
-     * @var array<string, ClassSchema|false>
+     * @var array<class-string,ClassSchema>
      */
     protected array $classSchemata = [];
 
     /**
      * An array of class names which are currently being forgotten by forgetClass(). Acts as a safeguard against infinite loops.
+     *
+     * @var array<class-string,true>
      */
     protected array $classesCurrentlyBeingForgotten = [];
 
     /**
      * Array with reflection information indexed by class name
+     *
+     * @var array<class-string,array{
+     *     1?: array<class-string,bool>,
+     *     3?: array<class-string,bool>,
+     *     5?: array<int,object>,
+     *     6?: true,
+     *     7?: true,
+     *     8?: array<string,array{
+     *         10?: true,
+     *         11?: true,
+     *         12: int,
+     *         13: array<string,array{
+     *             16: int,
+     *             17?: true,
+     *             18?: string,
+     *             19?: true,
+     *             20?: string,
+     *             21?: true,
+     *             22?: mixed,
+     *             23?: true,
+     *             24?: true,
+     *             25?: array<string,array<int,object>>
+     *         }>,
+     *         25: ?string
+     *     }>,
+     *     9?: array<string,array{
+     *         14?: array<int|string,array<mixed>>,
+     *         15?: array<string,array<int,object>>,
+     *         24?: int,
+     *         26?: string,
+     *         28?: true,
+     *     }>,
+     *     27?: true,
+     * }>
      */
     protected array $classReflectionData = [];
 
     /**
      * Array with updated reflection information (e.g. in Development context after classes have changed)
+     *
+     * @var array<class-string,true>
      */
     protected array $updatedReflectionData = [];
 
@@ -148,6 +198,8 @@ class ReflectionService
 
     /**
      * A runtime cache for reflected method annotations to speed up repeating checks.
+     *
+     * @var array<class-string,array<string,array<object>>>
      */
     protected array $methodAnnotationsRuntimeCache = [];
 
@@ -162,6 +214,9 @@ public function setClassSchemataRuntimeCache(VariableFrontend $cache): void
         $this->classSchemataRuntimeCache = $cache;
     }
 
+    /**
+     * @param array<string,mixed> $settings
+     */
     public function injectSettings(array $settings): void
     {
         $this->settings = $settings['reflection'];
@@ -211,7 +266,7 @@ protected function initialize(): void
      * This method is called by the Compile Time Object Manager which also determines
      * the list of classes to consider for reflection.
      *
-     * @param array $availableClassNames
+     * @param array<string,array<class-string>> $availableClassNames
      * @throws ClassLoadingForReflectionFailedException
      * @throws ClassSchemaConstraintViolationException
      * @throws Exception
@@ -234,7 +289,7 @@ public function buildReflectionData(array $availableClassNames): void
      * Tells if the specified class is known to this reflection service and
      * reflection information is available.
      *
-     * @param class-string $className
+     * @param string $className
      *
      * @api
      */
@@ -245,12 +300,13 @@ public function isClassReflected(string $className): bool
         }
         $className = $this->cleanClassName($className);
 
-        return isset($this->classReflectionData[$className]) && is_array($this->classReflectionData[$className]);
+        return array_key_exists($className, $this->classReflectionData);
     }
 
     /**
      * Returns the names of all classes known to this reflection service.
      *
+     * @return array<int,class-string>
      * @api
      */
     public function getAllClassNames(): array
@@ -318,6 +374,7 @@ public function getAllImplementationClassNamesForInterface(string $interfaceName
         }
         $interfaceName = $this->prepareClassReflectionForUsage($interfaceName);
 
+        /** @phpstan-ignore return.type (classic subtype dilemma; don't know how to solve it yet) */
         return array_keys($this->classReflectionData[$interfaceName][self::DATA_INTERFACE_IMPLEMENTATIONS] ?? []);
     }
 
@@ -325,8 +382,9 @@ public function getAllImplementationClassNamesForInterface(string $interfaceName
      * Searches for and returns all names of classes inheriting the specified class.
      * If no class inheriting the given class was found, an empty array is returned.
      *
-     * @param class-string $className
-     * @return array<class-string>
+     * @template T of object
+     * @param class-string<T> $className
+     * @return array<class-string<T>>
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -338,12 +396,15 @@ public function getAllSubClassNamesForClass(string $className): array
             throw new \InvalidArgumentException('"' . $className . '" does not exist or is not the name of a class.', 1257168042);
         }
         $className = $this->prepareClassReflectionForUsage($className);
+        /** @phpstan-ignore return.type (classic subtype dilemma; don't know how to solve it yet) */
         return array_keys($this->classReflectionData[$className][self::DATA_CLASS_SUBCLASSES] ?? []);
     }
 
     /**
      * Searches for and returns all names of classes which are tagged by the specified
      * annotation. If no classes were found, an empty array is returned.
+     *
+     * @return array<int,class-string>
      */
     public function getClassNamesByAnnotation(string $annotationClassName): array
     {
@@ -375,9 +436,10 @@ public function isClassAnnotatedWith(string $className, string $annotationClassN
     /**
      * Returns the specified class annotations or an empty array
      *
+     * @template T
      * @param class-string $className
-     * @param null|class-string $annotationClassName
-     * @return array<object>
+     * @param null|class-string<T> $annotationClassName
+     * @return ($annotationClassName is null ? array<int,object> : array<int,T>)
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -410,9 +472,10 @@ public function getClassAnnotations(string $className, string|null $annotationCl
      * If multiple annotations are set on the target you will
      * get the first instance of them.
      *
+     * @template T of object
      * @param class-string $className
-     * @param class-string $annotationClassName
-     * @return object|null
+     * @param class-string<T> $annotationClassName
+     * @return T|null
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -424,7 +487,7 @@ public function getClassAnnotation(string $className, string $annotationClassNam
         }
         $annotations = $this->getClassAnnotations($className, $annotationClassName);
 
-        return $annotations === [] ? null : reset($annotations);
+        return $annotations[0] ?? null;
     }
 
     /**
@@ -505,6 +568,7 @@ public function isClassUnconfigurable(string $className): bool
      * Returns all class names of classes containing at least one method annotated
      * with the given annotation class
      *
+     * @return array<int,class-string>
      * @api
      */
     public function getClassesContainingMethodsAnnotatedWith(string $annotationClassName): array
@@ -519,6 +583,7 @@ public function getClassesContainingMethodsAnnotatedWith(string $annotationClass
     /**
      * Returns all names of methods of the given class that are annotated with the given annotation class
      *
+     * @return array<string,string>
      * @api
      */
     public function getMethodsAnnotatedWith(string $className, string $annotationClassName): array
@@ -549,7 +614,7 @@ public function isMethodFinal(string $className, string $methodName): bool
     /**
      * Tells if the specified method is declared as static or not
      *
-     * @param class-string $className
+     * @param string $className
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -588,7 +653,6 @@ public function isMethodProtected(string $className, string $methodName): bool
     }
 
     /**
-     * @param class-string $className
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -643,9 +707,10 @@ public function isMethodAnnotatedWith(string $className, string $methodName, str
     /**
      * Returns the specified method annotations or an empty array
      *
+     * @template T
      * @param class-string $className
-     * @param class-string|null $annotationClassName
-     * @return array<object>
+     * @param class-string<T>|null $annotationClassName
+     * @return ($annotationClassName is null ? array<object> : array<T>)
      *
      * @throws \ReflectionException
      * @api
@@ -692,6 +757,10 @@ public function getMethodAnnotations(string $className, string $methodName, stri
      * If multiple annotations are set on the target you will
      * get the first instance of them.
      *
+     * @template T of object
+     * @param class-string $className
+     * @param class-string<T> $annotationClassName
+     *
      * @throws \ReflectionException
      */
     public function getMethodAnnotation(string $className, string $methodName, string $annotationClassName): ?object
@@ -740,6 +809,7 @@ public function hasMethod(string $className, string $methodName): bool
      *
      * @throws \ReflectionException
      * @deprecated since 8.4
+     * @return array<string,array<int,string>>
      */
     public function getMethodTagsValues(string $className, string $methodName): array
     {
@@ -756,7 +826,18 @@ public function getMethodTagsValues(string $className, string $methodName): arra
      * additional information about the parameter position, type hint etc.
      *
      * @param class-string $className
-     * @return array An array of parameter names and additional information or an empty array of no parameters were found
+     * @return array<string,array{
+     *      position: int,
+     *      optional: bool,
+     *      type: ?string,
+     *      class: ?string,
+     *      array: bool,
+     *      byReference: bool,
+     *      allowsNull: bool,
+     *      defaultValue: mixed,
+     *      scalarDeclaration: bool,
+     *      annotations: array<string,array<int,object>>,
+     * }> An array of parameter names and additional information or an empty array of no parameters were found
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -819,7 +900,7 @@ public function getPropertyNamesByTag(string $className, string $tag): array
      *
      * @param class-string $className
      * @param string $propertyName
-     * @return array
+     * @return array<int|string,array<mixed>>
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -837,7 +918,7 @@ public function getPropertyTagsValues(string $className, string $propertyName):
      * @param class-string $className
      * @param string $propertyName
      * @param string $tag
-     * @return array
+     * @return array<mixed>
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -958,10 +1039,11 @@ public function getPropertyNamesByAnnotation(string $className, string $annotati
     /**
      * Returns the specified property annotations or an empty array
      *
+     * @template Annotation of object
      * @param class-string $className
      * @param string $propertyName
-     * @param class-string|null $annotationClassName
-     * @return array<object>
+     * @param class-string<Annotation>|null $annotationClassName
+     * @return ($annotationClassName is null ? array<class-string,array<object>> : array<Annotation>)
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -978,6 +1060,9 @@ public function getPropertyAnnotations(string $className, string $propertyName,
             return $this->classReflectionData[$className][self::DATA_CLASS_PROPERTIES][$propertyName][self::DATA_PROPERTY_ANNOTATIONS];
         }
 
+        /** @phpstan-ignore return.type
+         * (in case of an annotation class name, this is really the annotation instance; The array iss just mixed with arbitrary-string-indexed other objects)
+         */
         return $this->classReflectionData[$className][self::DATA_CLASS_PROPERTIES][$propertyName][self::DATA_PROPERTY_ANNOTATIONS][$annotationClassName] ?? [];
     }
 
@@ -987,10 +1072,11 @@ public function getPropertyAnnotations(string $className, string $propertyName,
      * If multiple annotations are set on the target you will
      * get the first instance of them.
      *
-     * @param string $className
+     * @template Annotation of object
+     * @param class-string $className
      * @param string $propertyName
-     * @param string $annotationClassName
-     * @return object|null
+     * @param class-string<Annotation> $annotationClassName
+     * @return Annotation|null
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -1001,13 +1087,13 @@ public function getPropertyAnnotation(string $className, string $propertyName, s
             $this->initialize();
         }
         $annotations = $this->getPropertyAnnotations($className, $propertyName, $annotationClassName);
-        return $annotations === [] ? null : reset($annotations);
+        return reset($annotations) ?: null;
     }
 
     /**
      * Returns the class schema for the given class
      *
-     * @param class-string|object $classNameOrObject
+     * @param string|object $classNameOrObject
      * @return ClassSchema|null
      */
     public function getClassSchema(string|object $classNameOrObject): ?ClassSchema
@@ -1017,8 +1103,8 @@ public function getClassSchema(string|object $classNameOrObject): ?ClassSchema
         }
 
         $className = $classNameOrObject;
-        if (is_object($classNameOrObject)) {
-            $className = TypeHandling::getTypeForValue($classNameOrObject);
+        if (is_object($className)) {
+            $className = TypeHandling::getTypeForValue($className);
         }
         $className = $this->cleanClassName($className);
 
@@ -1033,8 +1119,8 @@ public function getClassSchema(string|object $classNameOrObject): ?ClassSchema
     /**
      * Initializes the ReflectionService, cleans the given class name and finally reflects the class if necessary.
      *
-     * @param class-string $className
-     * @return string
+     * @param string $className
+     * @return class-string
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -1123,7 +1209,7 @@ protected function isTagIgnored(string $tagName): bool
     /**
      * Reflects the given class and stores the results in this service's properties.
      *
-     * @param class-string $className
+     * @param string $className
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -1138,7 +1224,7 @@ protected function reflectClass(string $className): void
         }
 
         $class = new ClassReflection($className);
-        if (!isset($this->classReflectionData[$className]) || !is_array($this->classReflectionData[$className])) {
+        if (!array_key_exists($className, $this->classReflectionData)) {
             $this->classReflectionData[$className] = [];
         }
 
@@ -1194,6 +1280,7 @@ protected function reflectClass(string $className): void
     }
 
     /**
+     * @param class-string $className
      * @return int visibility
      */
     public function reflectClassProperty(string $className, PropertyReflection $property): int
@@ -1242,6 +1329,10 @@ public function reflectClassProperty(string $className, PropertyReflection $prop
         return $visibility;
     }
 
+    /**
+     * @param array<mixed> $tagValues
+     * @return array<mixed>|null
+     */
     protected function reflectPropertyTag(string $className, PropertyReflection $property, string $tagName, array $tagValues): ?array
     {
         if ($this->isTagIgnored($tagName)) {
@@ -1263,12 +1354,14 @@ protected function reflectPropertyTag(string $className, PropertyReflection $pro
     }
 
     /**
+     * @param class-string $className
      * @throws InvalidClassException
      * @throws ClassLoadingForReflectionFailedException
      * @throws \ReflectionException
      */
     protected function addParentClass(string $className, ClassReflection $parentClass): void
     {
+        /** @var class-string $parentClassName */
         $parentClassName = $parentClass->getName();
         if (!$this->isClassReflected($parentClassName)) {
             $this->loadOrReflectClassIfNecessary($parentClassName);
@@ -1277,6 +1370,7 @@ protected function addParentClass(string $className, ClassReflection $parentClas
     }
 
     /**
+     * @param class-string $className
      * @throws ClassLoadingForReflectionFailedException
      * @throws InvalidClassException
      * @throws \ReflectionException
@@ -1447,6 +1541,7 @@ protected function expandType(ClassReflection $class, string $type): string
     /**
      * Finds all parent classes of the given class
      *
+     * @param array<int,ClassReflection> $parentClasses
      * @return array<ClassReflection>
      */
     protected function getParentClasses(ClassReflection $class, array $parentClasses = []): array
@@ -1514,7 +1609,11 @@ protected function buildClassSchema(string $className): ClassSchema
         }
 
         $possibleRepositoryClassName = str_replace('\\Model\\', '\\Repository\\', $className) . 'Repository';
-        if ($this->isClassReflected($possibleRepositoryClassName) === true) {
+        if (
+            class_exists($possibleRepositoryClassName)
+            && is_subclass_of($possibleRepositoryClassName, RepositoryInterface::class)
+            && $this->isClassReflected($possibleRepositoryClassName) === true
+        ) {
             $classSchema->setRepositoryClassName($possibleRepositoryClassName);
         }
 
@@ -1540,7 +1639,6 @@ protected function addPropertiesToClassSchema(ClassSchema $classSchema): void
         $className = $classSchema->getClassName();
         $skipArtificialIdentity = false;
 
-        /* @var $valueObjectAnnotation Flow\ValueObject */
         $valueObjectAnnotation = $this->getClassAnnotation($className, Flow\ValueObject::class);
         if ($valueObjectAnnotation !== null && $valueObjectAnnotation->embedded === true) {
             $skipArtificialIdentity = true;
@@ -1594,6 +1692,9 @@ protected function evaluateClassPropertyAnnotationsForSchema(ClassSchema $classS
         }
 
         $declaredType = strtok(trim(current($varTagValues), " \n\t"), " \n\t");
+        if ($declaredType === false) {
+            throw new \Exception('Invalid type for ' . $className . '::$' . $propertyName, 1744046737);
+        }
 
         if ($this->isPropertyAnnotatedWith($className, $propertyName, ORM\Id::class)) {
             $skipArtificialIdentity = true;
@@ -1644,7 +1745,7 @@ protected function completeRepositoryAssignments(): void
         }
 
         foreach ($this->classSchemata as $classSchema) {
-            if ($classSchema instanceof ClassSchema && class_exists($classSchema->getClassName()) && $classSchema->isAggregateRoot()) {
+            if (class_exists($classSchema->getClassName()) && $classSchema->isAggregateRoot()) {
                 $this->makeChildClassesAggregateRoot($classSchema);
             }
         }
@@ -1684,7 +1785,7 @@ protected function makeChildClassesAggregateRoot(ClassSchema $classSchema): void
     protected function ensureAggregateRootInheritanceChainConsistency(): void
     {
         foreach ($this->classSchemata as $className => $classSchema) {
-            if (!class_exists($className) || ($classSchema instanceof ClassSchema && $classSchema->isAggregateRoot() === false)) {
+            if (!class_exists($className) || ($classSchema->isAggregateRoot() === false)) {
                 continue;
             }
 
@@ -1726,8 +1827,30 @@ protected function checkValueObjectRequirements(string $className): void
      * Converts the internal, optimized data structure of parameter information into
      * a human-friendly array with speaking indexes.
      *
-     * @param array $parametersInformation Raw, internal parameter information
-     * @return array Developer friendly version
+     * @param array<string,array{
+     *     16: int,
+     *     17?: true,
+     *     18?: string,
+     *     19?: true,
+     *     20?: string,
+     *     21?: true,
+     *     22?: mixed,
+     *     23?: true,
+     *     24?: true,
+     *     25?: array<string,array<int,object>>,
+     * }> $parametersInformation Raw, internal parameter information
+     * @return array<string,array{
+     *     position: int,
+     *     optional: bool,
+     *     type: ?string,
+     *     class: ?string,
+     *     array: bool,
+     *     byReference: bool,
+     *     allowsNull: bool,
+     *     defaultValue: mixed,
+     *     scalarDeclaration: bool,
+     *     annotations: array<string,array<int,object>>,
+     * }> Developer friendly version
      */
     protected function convertParameterDataToArray(array $parametersInformation): array
     {
@@ -1736,7 +1859,7 @@ protected function convertParameterDataToArray(array $parametersInformation): ar
             $parameters[$parameterName] = [
                 'position' => $parameterData[self::DATA_PARAMETER_POSITION],
                 'optional' => isset($parameterData[self::DATA_PARAMETER_OPTIONAL]),
-                'type' => $parameterData[self::DATA_PARAMETER_TYPE],
+                'type' => $parameterData[self::DATA_PARAMETER_TYPE] ?? null,
                 'class' => $parameterData[self::DATA_PARAMETER_CLASS] ?? null,
                 'array' => isset($parameterData[self::DATA_PARAMETER_ARRAY]),
                 'byReference' => isset($parameterData[self::DATA_PARAMETER_BY_REFERENCE]),
@@ -1753,7 +1876,18 @@ protected function convertParameterDataToArray(array $parametersInformation): ar
     /**
      * Converts the given parameter reflection into an information array
      *
-     * @return array Parameter information array
+     * @return array{
+     *     16: int,
+     *     17?: true,
+     *     18?: string,
+     *     19?: true,
+     *     20?: string,
+     *     21?: true,
+     *     22?: mixed,
+     *     23?: true,
+     *     24?: true,
+     *     25?: array<string,array<int,object>>
+     * } Parameter information array
      */
     protected function convertParameterReflectionToArray(ParameterReflection $parameter, MethodReflection $method): array
     {
@@ -1820,7 +1954,7 @@ protected function convertParameterReflectionToArray(ParameterReflection $parame
     protected function forgetChangedClasses(): void
     {
         foreach ($this->classReflectionData as $className => $_) {
-            if (is_string($className) && !$this->reflectionDataRuntimeCache->has($this->produceCacheIdentifierFromClassName($className))) {
+            if (!$this->reflectionDataRuntimeCache->has($this->produceCacheIdentifierFromClassName($className))) {
                 $this->forgetClass($className);
             }
         }
@@ -1953,10 +2087,16 @@ public function saveToCache(): void
 
     /**
      * Clean a given class name from possibly prefixed backslash
+     * @return class-string
      */
     protected function cleanClassName(string $className): string
     {
-        return ltrim($className, '\\');
+        $className = ltrim($className, '\\');
+        if (!class_exists($className)) {
+            throw new \Exception('Invalid class ' . $className, 1744047892);
+        }
+
+        return $className;
     }
 
     /**
@@ -1969,6 +2109,7 @@ protected function produceCacheIdentifierFromClassName(string $className): strin
 
     /**
      * Writes the given message along with the additional information into the log.
+     * @param array<string,mixed> $additionalData
      */
     protected function log(string $message, string $severity = LogLevel::INFO, array $additionalData = []): void
     {
@@ -1992,7 +2133,7 @@ function (\ReflectionNamedType|\ReflectionIntersectionType $type) {
                 $parameterType->getTypes()
             )),
             $parameterType instanceof \ReflectionIntersectionType => implode('&', array_map(
-                function (\ReflectionNamedType $type) {
+                function (\ReflectionType $type) {
                     return $this->renderParameterType($type);
                 },
                 $parameterType->getTypes()
diff --git a/Neos.Flow/Classes/Reflection/ReflectionServiceFactory.php b/Neos.Flow/Classes/Reflection/ReflectionServiceFactory.php
index e3e5ed1429..61ef500d0f 100644
--- a/Neos.Flow/Classes/Reflection/ReflectionServiceFactory.php
+++ b/Neos.Flow/Classes/Reflection/ReflectionServiceFactory.php
@@ -11,6 +11,7 @@
  * source code.
  */
 
+use Neos\Cache\Frontend\VariableFrontend;
 use Neos\Flow\Annotations as Flow;
 use Neos\Flow\Cache\CacheManager;
 use Neos\Flow\Configuration\ConfigurationManager;
@@ -62,8 +63,16 @@ public function create(): ReflectionService
         $reflectionService = new ReflectionService();
         $reflectionService->injectLogger($this->bootstrap->getEarlyInstance(PsrLoggerFactoryInterface::class)->get('systemLogger'));
         $reflectionService->injectSettings($settings);
-        $reflectionService->setReflectionDataRuntimeCache($cacheManager->getCache('Flow_Reflection_RuntimeData'));
-        $reflectionService->setClassSchemataRuntimeCache($cacheManager->getCache('Flow_Reflection_RuntimeClassSchemata'));
+        $runtimeDataCache = $cacheManager->getCache('Flow_Reflection_RuntimeData');
+        if (!$runtimeDataCache instanceof VariableFrontend) {
+            throw new \Exception('Cache Flow_Reflection_RuntimeData must have a VariableFrontend', 1743972055);
+        }
+        $reflectionService->setReflectionDataRuntimeCache($runtimeDataCache);
+        $runtimeClassSchemataCache = $cacheManager->getCache('Flow_Reflection_RuntimeClassSchemata');
+        if (!$runtimeClassSchemataCache instanceof VariableFrontend) {
+            throw new \Exception('Cache Flow_Reflection_RuntimeClassSchemata must have a VariableFrontend', 1743972058);
+        }
+        $reflectionService->setClassSchemataRuntimeCache($runtimeClassSchemataCache);
 
         $this->reflectionService = $reflectionService;
         return $reflectionService;
diff --git a/Neos.Flow/Classes/ResourceManagement/Collection.php b/Neos.Flow/Classes/ResourceManagement/Collection.php
index 6b07307bb0..275e85cf4c 100644
--- a/Neos.Flow/Classes/ResourceManagement/Collection.php
+++ b/Neos.Flow/Classes/ResourceManagement/Collection.php
@@ -40,7 +40,7 @@ class Collection implements CollectionInterface
     protected $target;
 
     /**
-     * @var array
+     * @var array<string>
      */
     protected $pathPatterns;
 
@@ -56,7 +56,7 @@ class Collection implements CollectionInterface
      * @param string $name User-space name of this collection, as specified in the settings
      * @param StorageInterface $storage The storage for data used in this collection
      * @param TargetInterface $target The publication target for this collection
-     * @param array $pathPatterns Glob patterns for paths to consider – only supported by specific storages
+     * @param array<string> $pathPatterns Glob patterns for paths to consider – only supported by specific storages
      */
     public function __construct($name, StorageInterface $storage, TargetInterface $target, array $pathPatterns)
     {
diff --git a/Neos.Flow/Classes/ResourceManagement/PersistentResource.php b/Neos.Flow/Classes/ResourceManagement/PersistentResource.php
index f431792dde..4e47d9f839 100644
--- a/Neos.Flow/Classes/ResourceManagement/PersistentResource.php
+++ b/Neos.Flow/Classes/ResourceManagement/PersistentResource.php
@@ -179,7 +179,7 @@ public function setFilename($filename)
         $this->throwExceptionIfProtected();
 
         $pathInfo = UnicodeFunctions::pathinfo($filename);
-        $extension = (isset($pathInfo['extension']) ? '.' . strtolower($pathInfo['extension']) : '');
+        $extension = '.' . strtolower($pathInfo['extension']);
         $this->filename = $pathInfo['filename'] . $extension;
         $this->mediaType = Utility\MediaTypes::getMediaTypeFromFilename($this->filename);
     }
@@ -298,10 +298,10 @@ public function getSha1()
      * @return void
      * @api
      */
-    public function setSha1($sha1)
+    public function setSha1(string $sha1)
     {
         $this->throwExceptionIfProtected();
-        if (!is_string($sha1) || preg_match('/[A-Fa-f0-9]{40}/', $sha1) !== 1) {
+        if (preg_match('/[A-Fa-f0-9]{40}/', $sha1) !== 1) {
             throw new \InvalidArgumentException('Specified invalid hash to setSha1()', 1362564220);
         }
         $this->sha1 = strtolower($sha1);
@@ -330,9 +330,9 @@ public function createTemporaryLocalCopy()
             $temporaryPathAndFilename .= '-' . microtime(true);
 
             if (function_exists('posix_getpid')) {
-                $temporaryPathAndFilename .= '-' . str_pad(posix_getpid(), 10);
+                $temporaryPathAndFilename .= '-' . str_pad((string)posix_getpid(), 10);
             } else {
-                $temporaryPathAndFilename .= '-' . (string) getmypid();
+                $temporaryPathAndFilename .= '-' . getmypid();
             }
 
             $temporaryPathAndFilename = trim($temporaryPathAndFilename);
@@ -364,7 +364,9 @@ public function postPersist()
     {
         if ($this->lifecycleEventsActive) {
             $collection = $this->resourceManager->getCollection($this->collectionName);
-            $collection->getTarget()->publishResource($this, $collection);
+            if ($collection) {
+                $collection->getTarget()->publishResource($this, $collection);
+            }
         }
     }
 
diff --git a/Neos.Flow/Classes/ResourceManagement/Publishing/MessageCollector.php b/Neos.Flow/Classes/ResourceManagement/Publishing/MessageCollector.php
index ffba74d24a..b5b6ecefc0 100644
--- a/Neos.Flow/Classes/ResourceManagement/Publishing/MessageCollector.php
+++ b/Neos.Flow/Classes/ResourceManagement/Publishing/MessageCollector.php
@@ -35,7 +35,7 @@ class MessageCollector
     ];
 
     /**
-     * @var \SplObjectStorage
+     * @var \SplObjectStorage<Message,mixed>
      */
     protected $messages;
 
diff --git a/Neos.Flow/Classes/ResourceManagement/ResourceManager.php b/Neos.Flow/Classes/ResourceManagement/ResourceManager.php
index 8956aa1770..c513b5bb7a 100644
--- a/Neos.Flow/Classes/ResourceManagement/ResourceManager.php
+++ b/Neos.Flow/Classes/ResourceManagement/ResourceManager.php
@@ -65,7 +65,7 @@ class ResourceManager
     protected $persistenceManager;
 
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $settings;
 
@@ -98,7 +98,7 @@ class ResourceManager
     /**
      * Injects the settings of this package
      *
-     * @param array $settings
+     * @param array<string,mixed> $settings
      * @return void
      */
     public function injectSettings(array $settings)
@@ -156,7 +156,6 @@ public function importResource($source, $collectionName = ResourceManager::DEFAU
             throw new Exception(sprintf('Tried to import a file into the resource collection "%s" but no such collection exists. Please check your settings and the code which triggered the import.', $collectionName), 1375196643);
         }
 
-        /* @var CollectionInterface $collection */
         $collection = $this->collections[$collectionName];
 
         try {
@@ -165,15 +164,17 @@ public function importResource($source, $collectionName = ResourceManager::DEFAU
                 ObjectAccess::setProperty($resource, 'Persistence_Object_Identifier', $forcedPersistenceObjectIdentifier, true);
             }
             if (!is_resource($source)) {
+                /** @var string $source */
                 $pathInfo = UnicodeFunctions::pathinfo($source);
+                /** @var PersistentResource $resource */
                 $resource->setFilename($pathInfo['basename']);
             }
         } catch (Exception $exception) {
             throw new Exception(sprintf('Importing a file into the resource collection "%s" failed: %s', $collectionName, $exception->getMessage()), 1375197120, $exception);
         }
-
+        /** @var PersistentResource $resource */
         $this->resourceRepository->add($resource);
-        $this->logger->debug(sprintf('Successfully imported file "%s" into the resource collection "%s" (storage: %s, a %s. SHA1: %s)', $source, $collectionName, $collection->getStorage()->getName(), get_class($collection), $resource->getSha1()));
+        $this->logger->debug(sprintf('Successfully imported file into the resource collection "%s" (storage: %s, a %s. SHA1: %s)', $collectionName, $collection->getStorage()->getName(), get_class($collection), $resource->getSha1()));
         return $resource;
     }
 
@@ -195,18 +196,14 @@ public function importResource($source, $collectionName = ResourceManager::DEFAU
      * @throws Exception
      * @api
      */
-    public function importResourceFromContent($content, $filename, $collectionName = ResourceManager::DEFAULT_PERSISTENT_COLLECTION_NAME, $forcedPersistenceObjectIdentifier = null)
+    public function importResourceFromContent(string $content, $filename, $collectionName = ResourceManager::DEFAULT_PERSISTENT_COLLECTION_NAME, $forcedPersistenceObjectIdentifier = null)
     {
-        if (!is_string($content)) {
-            throw new Exception(sprintf('Tried to import content into the resource collection "%s" but the given content was a %s instead of a string.', $collectionName, gettype($content)), 1380878115);
-        }
         $this->initialize();
 
         if (!isset($this->collections[$collectionName])) {
             throw new Exception(sprintf('Tried to import a file into the resource collection "%s" but no such collection exists. Please check your settings and the code which triggered the import.', $collectionName), 1380878131);
         }
 
-        /* @var CollectionInterface $collection */
         $collection = $this->collections[$collectionName];
 
         try {
@@ -219,6 +216,7 @@ public function importResourceFromContent($content, $filename, $collectionName =
             throw new Exception(sprintf('Importing content into the resource collection "%s" failed: %s', $collectionName, $exception->getMessage()), 1381156155, $exception);
         }
 
+        /** @var PersistentResource $resource */
         $this->resourceRepository->add($resource);
         $this->logger->debug(sprintf('Successfully imported content into the resource collection "%s" (storage: %s, a %s. SHA1: %s)', $collectionName, $collection->getStorage()->getName(), get_class($collection->getStorage()), $resource->getSha1()));
 
@@ -232,7 +230,7 @@ public function importResourceFromContent($content, $filename, $collectionName =
      * On a successful import this method returns a PersistentResource object representing
      * the newly imported persistent resource.
      *
-     * @param array $uploadInfo An array detailing the resource to import (expected keys: name, tmp_name)
+     * @param array<string,mixed> $uploadInfo An array detailing the resource to import (expected keys: name, tmp_name)
      * @param string $collectionName Name of the collection this uploaded resource should be added to
      * @return PersistentResource A resource object representing the imported resource
      * @throws Exception
@@ -303,7 +301,7 @@ public function getStreamByResource(PersistentResource $resource)
      * $resource2 => array('originalFilename' => 'Bar.txt'),
      * ...
      *
-     * @return \SplObjectStorage
+     * @return \SplObjectStorage<PersistentResource,mixed>
      * @api
      */
     public function getImportedResources()
@@ -449,7 +447,7 @@ public function getPublicPackageResourceUriByPath($path)
      * Return the package key and the relative path and filename from the given resource path
      *
      * @param string $path The ressource path, like resource://Your.Package/Public/Image/Dummy.png
-     * @return array The array contains two value, first the packageKey followed by the relativePathAndFilename
+     * @return array{0: string, 1: string} The array contains two value, first the packageKey followed by the relativePathAndFilename
      * @throws Exception
      * @api
      */
@@ -554,7 +552,10 @@ protected function initializeStorages()
             if (!class_exists($storageDefinition['storage'])) {
                 throw new Exception(sprintf('The configuration for the resource storage "%s" defined in your settings has not defined a valid "storage" option. Please check the configuration syntax and make sure that the specified class "%s" really exists.', $storageName, $storageDefinition['storage']), 1361467212);
             }
-            $options = (isset($storageDefinition['storageOptions']) ? $storageDefinition['storageOptions'] : []);
+            if (!is_subclass_of($storageDefinition['storage'], StorageInterface::class)) {
+                throw new Exception('Configured storage ' . $storageDefinition['storage'] . ' does not implement the required ' . StorageInterface::class, 1743970047);
+            }
+            $options = ($storageDefinition['storageOptions'] ?? []);
             $this->storages[$storageName] = new $storageDefinition['storage']($storageName, $options);
         }
     }
@@ -574,7 +575,10 @@ protected function initializeTargets()
             if (!class_exists($targetDefinition['target'])) {
                 throw new Exception(sprintf('The configuration for the resource target "%s" defined in your settings has not defined a valid "target" option. Please check the configuration syntax and make sure that the specified class "%s" really exists.', $targetName, $targetDefinition['target']), 1361467839);
             }
-            $options = (isset($targetDefinition['targetOptions']) ? $targetDefinition['targetOptions'] : []);
+            if (!is_subclass_of($targetDefinition['target'], TargetInterface::class)) {
+                throw new Exception('Configured resource target ' . $targetDefinition['target'] . ' does not implement the required ' . TargetInterface::class, 1743969958);
+            }
+            $options = $targetDefinition['targetOptions'] ?? [];
             $this->targets[$targetName] = new $targetDefinition['target']($targetName, $options);
         }
     }
@@ -612,21 +616,24 @@ protected function initializeCollections()
      * Prepare an uploaded file to be imported as resource object. Will check the validity of the file,
      * move it outside of upload folder if open_basedir is enabled and check the filename.
      *
-     * @param array $uploadInfo
-     * @return array Array of string with the two keys "filepath" (the path to get the filecontent from) and "filename" the filename of the originally uploaded file.
+     * @param array<string,mixed> $uploadInfo
+     * @return array{filepath: string, filename: string} Array of string with the two keys "filepath" (the path to get the filecontent from) and "filename" the filename of the originally uploaded file.
      * @throws Exception
      */
     protected function prepareUploadedFileForImport(array $uploadInfo)
     {
         $openBasedirEnabled = (boolean)ini_get('open_basedir');
-        $temporaryTargetPathAndFilename = $uploadInfo['tmp_name'];
+        $temporaryTargetPathAndFilename = $uploadInfo['tmp_name'] ?? null;
+        if (!is_string($temporaryTargetPathAndFilename)) {
+            throw new \Exception('String tmp_name required', 1743969722);
+        }
         $pathInfo = UnicodeFunctions::pathinfo($uploadInfo['name']);
 
         if (!is_uploaded_file($temporaryTargetPathAndFilename)) {
             throw new Exception('The given upload file "' . strip_tags($pathInfo['basename']) . '" was not uploaded through PHP. As it could pose a security risk it cannot be imported.', 1422461503);
         }
 
-        if (isset($pathInfo['extension']) && array_key_exists(strtolower($pathInfo['extension']), $this->settings['extensionsBlockedFromUpload']) && $this->settings['extensionsBlockedFromUpload'][strtolower($pathInfo['extension'])] === true) {
+        if (array_key_exists(strtolower($pathInfo['extension']), $this->settings['extensionsBlockedFromUpload']) && $this->settings['extensionsBlockedFromUpload'][strtolower($pathInfo['extension'])] === true) {
             throw new Exception('The extension of the given upload file "' . strip_tags($pathInfo['basename']) . '" is excluded. As it could pose a security risk it cannot be imported.', 1447148472);
         }
 
@@ -645,7 +652,7 @@ protected function prepareUploadedFileForImport(array $uploadInfo)
 
         return [
             'filepath' => $temporaryTargetPathAndFilename,
-            'filename' => $pathInfo['basename']
+            'filename' => $pathInfo['basename'],
         ];
     }
 }
diff --git a/Neos.Flow/Classes/ResourceManagement/ResourceMetaDataInterface.php b/Neos.Flow/Classes/ResourceManagement/ResourceMetaDataInterface.php
index 8cd9b10a9d..89556eac2e 100644
--- a/Neos.Flow/Classes/ResourceManagement/ResourceMetaDataInterface.php
+++ b/Neos.Flow/Classes/ResourceManagement/ResourceMetaDataInterface.php
@@ -80,5 +80,5 @@ public function getSha1();
      * @param string $sha1 The sha1 hash
      * @return void
      */
-    public function setSha1($sha1);
+    public function setSha1(string $sha1);
 }
diff --git a/Neos.Flow/Classes/ResourceManagement/ResourceRepository.php b/Neos.Flow/Classes/ResourceManagement/ResourceRepository.php
index 82bb9dcf7a..605ba63894 100644
--- a/Neos.Flow/Classes/ResourceManagement/ResourceRepository.php
+++ b/Neos.Flow/Classes/ResourceManagement/ResourceRepository.php
@@ -48,12 +48,12 @@ class ResourceRepository extends Repository
     protected $persistenceManager;
 
     /**
-     * @var \SplObjectStorage|PersistentResource[]
+     * @var \SplObjectStorage<PersistentResource,mixed>
      */
     protected $removedResources;
 
     /**
-     * @var \SplObjectStorage|PersistentResource[]
+     * @var \SplObjectStorage<PersistentResource,mixed>
      */
     protected $addedResources;
 
@@ -73,6 +73,9 @@ public function __construct()
      */
     public function add($object): void
     {
+        if (!($object instanceof PersistentResource)) {
+            throw new \Exception('Can only add objects of type PersistentResource', 1743969457);
+        }
         $this->persistenceManager->allowObject($object);
         if ($this->removedResources->contains($object)) {
             $this->removedResources->detach($object);
@@ -91,6 +94,9 @@ public function add($object): void
      */
     public function remove($object): void
     {
+        if (!($object instanceof PersistentResource)) {
+            throw new \Exception('Can only remove objects of type PersistentResource', 1743969438);
+        }
         // Intercept a second call for the same PersistentResource object because it might cause an endless loop caused by
         // the ResourceManager's deleteResource() method which also calls this remove() function:
         if (!$this->removedResources->contains($object)) {
@@ -188,7 +194,7 @@ public function findSimilarResources(PersistentResource $resource)
      * Find all resources with the same SHA1 hash
      *
      * @param string $sha1Hash
-     * @return array
+     * @return array<PersistentResource>
      */
     public function findBySha1($sha1Hash)
     {
@@ -209,7 +215,7 @@ public function findBySha1($sha1Hash)
      *
      * @param string $sha1Hash
      * @param string $collectionName
-     * @return array
+     * @return array<PersistentResource>
      */
     public function findBySha1AndCollectionName($sha1Hash, $collectionName)
     {
@@ -261,16 +267,15 @@ public function countBySha1AndCollectionName(string $sha1Hash, string $collectio
      * Find one resource by SHA1
      *
      * @param string $sha1Hash
-     * @return PersistentResource
+     * @return ?PersistentResource
      */
     public function findOneBySha1($sha1Hash)
     {
         $query = $this->createQuery();
         $query->matching($query->equals('sha1', $sha1Hash))->setLimit(1);
-        /** @var PersistentResource $resource */
+        /** @var ?PersistentResource $resource */
         $resource = $query->execute()->getFirst();
         if ($resource === null) {
-            /** @var PersistentResource $importedResource */
             foreach ($this->addedResources as $importedResource) {
                 if ($importedResource->getSha1() === $sha1Hash) {
                     return $importedResource;
@@ -282,7 +287,7 @@ public function findOneBySha1($sha1Hash)
     }
 
     /**
-     * @return \SplObjectStorage
+     * @return \SplObjectStorage<PersistentResource,mixed>
      */
     public function getAddedResources()
     {
diff --git a/Neos.Flow/Classes/ResourceManagement/ResourceTypeConverter.php b/Neos.Flow/Classes/ResourceManagement/ResourceTypeConverter.php
index fc81836e5b..cb806ee1d2 100644
--- a/Neos.Flow/Classes/ResourceManagement/ResourceTypeConverter.php
+++ b/Neos.Flow/Classes/ResourceManagement/ResourceTypeConverter.php
@@ -119,7 +119,7 @@ class ResourceTypeConverter extends AbstractTypeConverter
     protected $logger;
 
     /**
-     * @var array
+     * @var array<string,PersistentResource>
      */
     protected $convertedResources = [];
 
@@ -144,9 +144,9 @@ public function injectLogger(LoggerInterface $logger)
      * Note that $source['error'] will also be present if a file was successfully
      * uploaded. In that case its value will be \UPLOAD_ERR_OK.
      *
-     * @param array|string|UploadedFileInterface $source The upload info (expected keys: error, name, tmp_name), the hash or an UploadedFile
+     * @param array<string,mixed>|string|UploadedFileInterface $source The upload info (expected keys: error, name, tmp_name), the hash or an UploadedFile
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return PersistentResource|null|FlowError if the input format is not supported or could not be converted for other reasons
      * @throws Exception
@@ -177,7 +177,7 @@ public function convertFrom($source, $targetType, array $convertedChildPropertie
     }
 
     /**
-     * @param array $source
+     * @param array<string,mixed> $source
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return PersistentResource|null|FlowError
      */
@@ -219,7 +219,7 @@ protected function handleFileUploads(array $source, ?PropertyMappingConfiguratio
     }
 
     /**
-     * @param array $source
+     * @param array<string,mixed> $source
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return PersistentResource|FlowError
      * @throws Exception
@@ -256,12 +256,13 @@ protected function handleHashAndData(array $source, ?PropertyMappingConfiguratio
             if (isset($source['data']) && isset($source['filename'])) {
                 $resource = $this->resourceManager->importResourceFromContent(base64_decode($source['data']), $source['filename'], $collectionName, $givenResourceIdentity);
             } elseif ($hash !== null) {
-                $resource = $this->resourceManager->importResource($configuration->getConfigurationValue(ResourceTypeConverter::class, self::CONFIGURATION_RESOURCE_LOAD_PATH) . '/' . $hash, $collectionName, $givenResourceIdentity);
-                if (is_array($source) && isset($source['filename'])) {
-                    $resource->setFilename($source['filename']);
+                $resource = $this->resourceManager->importResource($configuration?->getConfigurationValue(ResourceTypeConverter::class, self::CONFIGURATION_RESOURCE_LOAD_PATH) . '/' . $hash, $collectionName, $givenResourceIdentity);
+                $filename = $source['filename'] ?? null;
+                if (is_string($filename)) {
+                    $resource->setFilename($filename);
                 }
             }
-            if ($hash !== null && $resource->getSha1() !== $hash) {
+            if ($hash !== null && $resource?->getSha1() !== $hash) {
                 throw new Exception\InvalidResourceDataException('The source SHA1 did not match the SHA1 of the imported resource.', 1482248149);
             }
         }
@@ -297,7 +298,7 @@ protected function handleUploadedFile(UploadedFileInterface $source, ?PropertyMa
             case \UPLOAD_ERR_PARTIAL:
                 return new FlowError(Files::getUploadErrorMessage($source->getError()), 1264440823);
             default:
-                $this->logger->error(sprintf('A server error occurred while converting an uploaded resource: "%s"', Files::getUploadErrorMessage($source['error'])), LogEnvironment::fromMethodName(__METHOD__));
+                $this->logger->error(sprintf('A server error occurred while converting an uploaded resource: "%s"', Files::getUploadErrorMessage($source->getError())), LogEnvironment::fromMethodName(__METHOD__));
 
                 return new FlowError('An error occurred while uploading. Please try again or contact the administrator if the problem remains', 1340193849);
         }
@@ -307,8 +308,15 @@ protected function handleUploadedFile(UploadedFileInterface $source, ?PropertyMa
         }
 
         try {
-            $resource = $this->resourceManager->importResource($source->getStream()->detach(), $this->getCollectionName($source, $configuration));
-            $resource->setFilename($source->getClientFilename());
+            $sourceForImport = $source->getStream()->detach();
+            if ($sourceForImport === null) {
+                throw new \Exception('Failed to detach resource from stream', 1743967911);
+            }
+            $resource = $this->resourceManager->importResource($sourceForImport, $this->getCollectionName($source, $configuration));
+            $filename = $source->getClientFilename();
+            if ($filename !== null) {
+                $resource->setFilename($filename);
+            }
             $this->convertedResources[spl_object_hash($source)] = $resource;
             return $resource;
         } catch (\Exception $exception) {
@@ -324,7 +332,7 @@ protected function handleUploadedFile(UploadedFileInterface $source, ?PropertyMa
      * The propertyMappingConfiguration CONFIGURATION_COLLECTION_NAME will directly override the default. Then if CONFIGURATION_ALLOW_COLLECTION_OVERRIDE is true
      * and __collectionName is in the $source this will finally be the value.
      *
-     * @param array|UploadedFileInterface $source
+     * @param array<string,mixed>|UploadedFileInterface $source
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return string
      * @throws InvalidPropertyMappingConfigurationException
diff --git a/Neos.Flow/Classes/ResourceManagement/Storage/FileSystemStorage.php b/Neos.Flow/Classes/ResourceManagement/Storage/FileSystemStorage.php
index 6e4f0536cf..ad0ee6580c 100644
--- a/Neos.Flow/Classes/ResourceManagement/Storage/FileSystemStorage.php
+++ b/Neos.Flow/Classes/ResourceManagement/Storage/FileSystemStorage.php
@@ -59,7 +59,7 @@ class FileSystemStorage implements StorageInterface
      * Constructor
      *
      * @param string $name Name of this storage instance, according to the resource settings
-     * @param array $options Options for this storage
+     * @param array<string,mixed> $options Options for this storage
      * @throws Exception
      */
     public function __construct($name, array $options = [])
diff --git a/Neos.Flow/Classes/ResourceManagement/Storage/PackageStorage.php b/Neos.Flow/Classes/ResourceManagement/Storage/PackageStorage.php
index d0ff7285aa..23ead9adba 100644
--- a/Neos.Flow/Classes/ResourceManagement/Storage/PackageStorage.php
+++ b/Neos.Flow/Classes/ResourceManagement/Storage/PackageStorage.php
@@ -71,7 +71,10 @@ public function getObjectsByPathPattern($pattern)
             if ($directoryPattern === '*') {
                 $directories[$packageKey][] = $package->getPackagePath();
             } else {
-                $directories[$packageKey] = glob($package->getPackagePath() . $directoryPattern, GLOB_ONLYDIR);
+                $packageDirectories = glob($package->getPackagePath() . $directoryPattern, GLOB_ONLYDIR);
+                if ($packageDirectories !== false) {
+                    $directories[$packageKey] = $packageDirectories;
+                }
             }
         }
 
@@ -98,11 +101,15 @@ protected function createStorageObject($resourcePathAndFilename, FlowPackageInte
 
         $object = new StorageObject();
         $object->setFilename($pathInfo['basename']);
-        $object->setSha1(sha1_file($resourcePathAndFilename));
-        $object->setFileSize(filesize($resourcePathAndFilename));
-        if (isset($pathInfo['dirname'])) {
-            $object->setRelativePublicationPath($this->prepareRelativePublicationPath($pathInfo['dirname'], $resourcePackage->getPackageKey(), $resourcePackage->getResourcesPath()));
+        $sha1 = sha1_file($resourcePathAndFilename);
+        if ($sha1 !== false) {
+            $object->setSha1($sha1);
+        }
+        $fileSize = filesize($resourcePathAndFilename);
+        if ($fileSize !== false) {
+            $object->setFileSize($fileSize);
         }
+        $object->setRelativePublicationPath($this->prepareRelativePublicationPath($pathInfo['dirname'], $resourcePackage->getPackageKey(), $resourcePackage->getResourcesPath()));
         $object->setStream(function () use ($resourcePathAndFilename) {
             return fopen($resourcePathAndFilename, 'r');
         });
diff --git a/Neos.Flow/Classes/ResourceManagement/Storage/StorageObject.php b/Neos.Flow/Classes/ResourceManagement/Storage/StorageObject.php
index 40dc365534..53d37a923e 100644
--- a/Neos.Flow/Classes/ResourceManagement/Storage/StorageObject.php
+++ b/Neos.Flow/Classes/ResourceManagement/Storage/StorageObject.php
@@ -98,7 +98,7 @@ public function getMediaType()
     public function setFilename($filename)
     {
         $pathInfo = UnicodeFunctions::pathinfo($filename);
-        $extension = (isset($pathInfo['extension']) ? '.' . strtolower($pathInfo['extension']) : '');
+        $extension = '.' . strtolower($pathInfo['extension']);
         $this->filename = $pathInfo['filename'] . $extension;
         $this->mediaType = MediaTypes::getMediaTypeFromFilename($this->filename);
     }
@@ -201,7 +201,11 @@ public function setStream($stream)
     public function getStream()
     {
         if ($this->stream instanceof \Closure) {
-            $this->stream = $this->stream->__invoke();
+            $resource = $this->stream->__invoke();
+            if (!is_resource($resource)) {
+                throw new \Exception('Failed to resolve resource from closure', 1743962813);
+            }
+            $this->stream = $resource;
         }
         if (is_resource($this->stream)) {
             $meta = stream_get_meta_data($this->stream);
diff --git a/Neos.Flow/Classes/ResourceManagement/Storage/WritableFileSystemStorage.php b/Neos.Flow/Classes/ResourceManagement/Storage/WritableFileSystemStorage.php
index 1974e75a6c..f841a53aa8 100644
--- a/Neos.Flow/Classes/ResourceManagement/Storage/WritableFileSystemStorage.php
+++ b/Neos.Flow/Classes/ResourceManagement/Storage/WritableFileSystemStorage.php
@@ -57,12 +57,16 @@ public function importResource($source, $collectionName)
         if (is_resource($source)) {
             try {
                 $target = fopen($temporaryTargetPathAndFilename, 'wb');
+                if ($target === false) {
+                    throw new \Exception('Failed to open ' . $temporaryTargetPathAndFilename, 1743964877);
+                }
                 stream_copy_to_stream($source, $target);
                 fclose($target);
             } catch (\Exception $exception) {
                 throw new StorageException(sprintf('Could import the content stream to temporary file "%s".', $temporaryTargetPathAndFilename), 1380880079);
             }
         } else {
+            /** @var string $source */
             if (copy($source, $temporaryTargetPathAndFilename) === false) {
                 throw new StorageException(sprintf('Could not copy the file from "%s" to temporary file "%s".', $source, $temporaryTargetPathAndFilename), 1375198876);
             }
@@ -130,6 +134,9 @@ protected function importTemporaryFile($temporaryPathAndFileName, $collectionNam
     {
         $this->fixFilePermissions($temporaryPathAndFileName);
         $sha1Hash = sha1_file($temporaryPathAndFileName);
+        if ($sha1Hash === false) {
+            throw new \Exception('Failed to resolve sha1 hash for ' . $temporaryPathAndFileName);
+        }
         $targetPathAndFilename = $this->getStoragePathAndFilenameByHash($sha1Hash);
 
         if (!is_file($targetPathAndFilename)) {
@@ -139,7 +146,10 @@ protected function importTemporaryFile($temporaryPathAndFileName, $collectionNam
         }
 
         $resource = new PersistentResource();
-        $resource->setFileSize(filesize($targetPathAndFilename));
+        $fileSize = filesize($targetPathAndFilename);
+        if ($fileSize !== false) {
+            $resource->setFileSize($fileSize);
+        }
         $resource->setCollectionName($collectionName);
         $resource->setSha1($sha1Hash);
 
diff --git a/Neos.Flow/Classes/ResourceManagement/Streams/ResourceStreamWrapper.php b/Neos.Flow/Classes/ResourceManagement/Streams/ResourceStreamWrapper.php
index 752ce47558..6117b75326 100644
--- a/Neos.Flow/Classes/ResourceManagement/Streams/ResourceStreamWrapper.php
+++ b/Neos.Flow/Classes/ResourceManagement/Streams/ResourceStreamWrapper.php
@@ -88,7 +88,7 @@ public function closeDirectory()
      * This method is called in response to opendir().
      *
      * @param string $path Specifies the URL that was passed to opendir().
-     * @param int $options Whether or not to enforce safe_mode (0x04).
+     * @param int $options Whether to enforce safe_mode (0x04).
      * @return boolean true on success or false on failure.
      */
     public function openDirectory($path, $options)
@@ -97,7 +97,7 @@ public function openDirectory($path, $options)
         if (!is_string($resourceUriOrStream)) {
             return false;
         }
-        $handle = ($resourceUriOrStream !== false) ? opendir($resourceUriOrStream) : false;
+        $handle = opendir($resourceUriOrStream);
         if ($handle !== false) {
             $this->handle = $handle;
             return true;
@@ -110,7 +110,7 @@ public function openDirectory($path, $options)
      *
      * This method is called in response to readdir().
      *
-     * @return string Should return string representing the next filename, or false if there is no next file.
+     * @return string|false Should return string representing the next filename, or false if there is no next file.
      */
     public function readDirectory()
     {
@@ -148,7 +148,7 @@ public function makeDirectory($path, $mode, $options)
     {
         $resourceUriOrStream = $this->evaluateResourcePath($path, false);
         if (is_string($resourceUriOrStream)) {
-            return mkdir($resourceUriOrStream, $mode, $options&STREAM_MKDIR_RECURSIVE);
+            return mkdir($resourceUriOrStream, $mode, (bool)($options&STREAM_MKDIR_RECURSIVE));
         }
         return false;
     }
@@ -309,10 +309,11 @@ public function open($path, $mode, $options, &$openedPathAndFilename)
             $this->handle = $resourceUriOrStream;
             return true;
         }
-
+        /** @var string|false $resourceUriOrStream */
         $handle = ($resourceUriOrStream !== false) ? fopen($resourceUriOrStream, $mode) : false;
         if ($handle !== false) {
             $this->handle = $handle;
+            /** @var string $resourceUriOrStream */
             $openedPathAndFilename = $resourceUriOrStream;
             return true;
         }
@@ -328,10 +329,13 @@ public function open($path, $mode, $options, &$openedPathAndFilename)
      * number of bytes that were successfully read).
      *
      * @param integer $count How many bytes of data from the current position should be returned.
-     * @return string If there are less than count bytes available, return as many as are available. If no more data is available, return either false or an empty string.
+     * @return string|false If there are less than count bytes available, return as many as are available. If no more data is available, return either false or an empty string.
      */
     public function read($count)
     {
+        if ($count < 1) {
+            throw new \Exception('Cannot read less than one byte', 1743964166);
+        }
         return fread($this->handle, $count);
     }
 
@@ -392,7 +396,7 @@ public function setOption($option, $argument1, $argument2)
      *
      * This method is called in response to ftell().
      *
-     * @return int Should return the current position of the stream.
+     * @return int|false Should return the current position of the stream.
      */
     public function tell()
     {
@@ -411,7 +415,7 @@ public function tell()
      * bytes that were successfully written.
      *
      * @param string $data Should be stored into the underlying stream.
-     * @return int Should return the number of bytes that were successfully stored, or 0 if none could be stored.
+     * @return int|false Should return the number of bytes that were successfully stored, or 0 if none could be stored.
      */
     public function write($data)
     {
@@ -441,7 +445,7 @@ public function unlink($path)
      *
      * This method is called in response to fstat().
      *
-     * @return array See http://php.net/stat
+     * @return array<int|string, int>|false See http://php.net/stat
      */
     public function resourceStat()
     {
@@ -472,14 +476,18 @@ public function resourceStat()
      *
      * @param string $path The file path or URL to stat. Note that in the case of a URL, it must be a :// delimited URL. Other URL forms are not supported.
      * @param integer $flags Holds additional flags set by the streams API.
-     * @return array Should return as many elements as stat() does. Unknown or unavailable values should be set to a rational value (usually 0).
+     * @return array<int|string, int>|false Should return as many elements as stat() does. Unknown or unavailable values should be set to a rational value (usually 0).
      */
     public function pathStat($path, $flags)
     {
         $evaluatedResourcePath = $this->evaluateResourcePath($path);
+        if ($evaluatedResourcePath === false) {
+            return false;
+        }
         if (is_resource($evaluatedResourcePath)) {
             return @fstat($evaluatedResourcePath);
         }
+        /** @var string $evaluatedResourcePath */
         return @stat($evaluatedResourcePath);
     }
 
@@ -489,7 +497,7 @@ public function pathStat($path, $flags)
      *
      * @param string $requestedPath
      * @param boolean $checkForExistence Whether a (non-hash) path should be checked for existence before being returned
-     * @return mixed The full path and filename or false if the file doesn't exist
+     * @return string|resource|false The full path and filename or false if the file doesn't exist
      * @throws \InvalidArgumentException|ResourceException
      */
     protected function evaluateResourcePath($requestedPath, $checkForExistence = true)
@@ -507,7 +515,7 @@ protected function evaluateResourcePath($requestedPath, $checkForExistence = tru
 
         if (strpos($resourceUriWithoutScheme, '/') === false && preg_match('/^[0-9a-f]{40}$/i', $resourceUriWithoutScheme) === 1) {
             $resource = $this->resourceManager->getResourceBySha1($resourceUriWithoutScheme);
-            return $this->resourceManager->getStreamByResource($resource);
+            return $resource ? $this->resourceManager->getStreamByResource($resource) : false;
         }
 
         list($packageName, $path) = explode('/', $resourceUriWithoutScheme, 2);
diff --git a/Neos.Flow/Classes/ResourceManagement/Streams/StreamWrapperAdapter.php b/Neos.Flow/Classes/ResourceManagement/Streams/StreamWrapperAdapter.php
index adec60d7fc..a75a876278 100644
--- a/Neos.Flow/Classes/ResourceManagement/Streams/StreamWrapperAdapter.php
+++ b/Neos.Flow/Classes/ResourceManagement/Streams/StreamWrapperAdapter.php
@@ -28,7 +28,7 @@
 class StreamWrapperAdapter
 {
     /**
-     * @var array
+     * @var array<string,class-string<StreamWrapperInterface>> indexed by scheme
      */
     protected static $registeredStreamWrappers = [];
 
@@ -51,7 +51,6 @@ class StreamWrapperAdapter
     public static function initializeStreamWrapper($objectManager)
     {
         $streamWrapperClassNames = static::getStreamWrapperImplementationClassNames($objectManager);
-        /** @var StreamWrapperInterface $streamWrapperClassName */
         foreach ($streamWrapperClassNames as $streamWrapperClassName) {
             $scheme = $streamWrapperClassName::getScheme();
             if (in_array($scheme, stream_get_wrappers())) {
@@ -67,7 +66,7 @@ public static function initializeStreamWrapper($objectManager)
      * earlier ones without warning.
      *
      * @param string $scheme
-     * @param string $objectName
+     * @param class-string<StreamWrapperInterface> $objectName
      * @return void
      */
     public static function registerStreamWrapper($scheme, $objectName)
@@ -78,7 +77,7 @@ public static function registerStreamWrapper($scheme, $objectName)
     /**
      * Returns the stream wrappers registered with this class.
      *
-     * @return array
+     * @return array<string,class-string<StreamWrapperInterface>> indexed by scheme
      */
     public static function getRegisteredStreamWrappers()
     {
@@ -226,7 +225,7 @@ public function rmdir($path, $options)
      * This method is called in response to stream_select().
      *
      * @param integer $cast_as Can be STREAM_CAST_FOR_SELECT when stream_select() is calling stream_cast() or STREAM_CAST_AS_STREAM when stream_cast() is called for other uses.
-     * @return resource Should return the underlying stream resource used by the wrapper, or false.
+     * @return resource|false Should return the underlying stream resource used by the wrapper, or false.
      */
     public function stream_cast($cast_as)
     {
@@ -401,7 +400,7 @@ public function stream_set_option($option, $arg1, $arg2)
      *
      * This method is called in response to fstat().
      *
-     * @return array See http://php.net/stat
+     * @return array<string,int> See http://php.net/stat
      */
     public function stream_stat()
     {
@@ -476,7 +475,7 @@ public function unlink($path)
      *
      * @param string $path The file path or URL to stat. Note that in the case of a URL, it must be a :// delimited URL. Other URL forms are not supported.
      * @param integer $flags Holds additional flags set by the streams API.
-     * @return array Should return as many elements as stat() does. Unknown or unavailable values should be set to a rational value (usually 0).
+     * @return array<int|string, int>|false Should return as many elements as stat() does. Unknown or unavailable values should be set to a rational value (usually 0).
      */
     public function url_stat($path, $flags)
     {
@@ -488,7 +487,7 @@ public function url_stat($path, $flags)
      * Returns all class names implementing the StreamWrapperInterface.
      *
      * @param ObjectManagerInterface $objectManager
-     * @return array Array of stream wrapper implementations
+     * @return array<class-string<StreamWrapperInterface>> Array of stream wrapper implementations
      * @Flow\CompileStatic
      */
     public static function getStreamWrapperImplementationClassNames(ObjectManagerInterface $objectManager)
diff --git a/Neos.Flow/Classes/ResourceManagement/Streams/StreamWrapperInterface.php b/Neos.Flow/Classes/ResourceManagement/Streams/StreamWrapperInterface.php
index 13365e92c6..11e91d18a1 100644
--- a/Neos.Flow/Classes/ResourceManagement/Streams/StreamWrapperInterface.php
+++ b/Neos.Flow/Classes/ResourceManagement/Streams/StreamWrapperInterface.php
@@ -335,7 +335,7 @@ public function unlink($path);
      *
      * This method is called in response to fstat().
      *
-     * @return array See http://php.net/stat
+     * @return array<string,int> See http://php.net/stat
      * @api
      */
     public function resourceStat();
@@ -359,7 +359,7 @@ public function resourceStat();
      *
      * @param string $path The file path or URL to stat. Note that in the case of a URL, it must be a :// delimited URL. Other URL forms are not supported.
      * @param integer $flags Holds additional flags set by the streams API.
-     * @return array Should return as many elements as stat() does. Unknown or unavailable values should be set to a rational value (usually 0).
+     * @return array<int|string, int>|false Should return as many elements as stat() does. Unknown or unavailable values should be set to a rational value (usually 0).
      * @api
      */
     public function pathStat($path, $flags);
diff --git a/Neos.Flow/Classes/ResourceManagement/Target/FileSystemSymlinkTarget.php b/Neos.Flow/Classes/ResourceManagement/Target/FileSystemSymlinkTarget.php
index f6e808cdbe..34a83aac88 100644
--- a/Neos.Flow/Classes/ResourceManagement/Target/FileSystemSymlinkTarget.php
+++ b/Neos.Flow/Classes/ResourceManagement/Target/FileSystemSymlinkTarget.php
@@ -62,7 +62,7 @@ protected function publishFile($sourceStream, $relativeTargetPathAndFilename)
     {
         $extension = strtolower(pathinfo($relativeTargetPathAndFilename, PATHINFO_EXTENSION));
         if ($extension !== '' && array_key_exists($extension, $this->excludedExtensions) && $this->excludedExtensions[$extension] === true) {
-            throw new TargetException(sprintf('Could not publish "%s" into resource publishing target "%s" because the filename extension "%s" is excluded.', $sourceStream, $this->name, $extension), 1447152230);
+            throw new TargetException(sprintf('Could not publish resource into publishing target "%s" because the filename extension "%s" is excluded.', $this->name, $extension), 1447152230);
         }
 
         $streamMetaData = stream_get_meta_data($sourceStream);
@@ -151,6 +151,9 @@ protected function setOption($key, $value)
         return parent::setOption($key, $value);
     }
 
+    /**
+     * @return array{0: bool, 1: ?\Exception}
+     */
     private function publish(string $targetPathAndFilename, string $sourcePathAndFilename): array
     {
         $exception = null;
diff --git a/Neos.Flow/Classes/ResourceManagement/Target/FileSystemTarget.php b/Neos.Flow/Classes/ResourceManagement/Target/FileSystemTarget.php
index f30d54274b..3d6c8bf149 100644
--- a/Neos.Flow/Classes/ResourceManagement/Target/FileSystemTarget.php
+++ b/Neos.Flow/Classes/ResourceManagement/Target/FileSystemTarget.php
@@ -33,7 +33,7 @@
 class FileSystemTarget implements TargetInterface
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $options = [];
 
@@ -83,7 +83,7 @@ class FileSystemTarget implements TargetInterface
     /**
      * A list of extensions that are excluded and must not be published by this target.
      *
-     * @var array
+     * @var array<string,bool>
      */
     protected $excludedExtensions = [];
 
@@ -115,7 +115,7 @@ class FileSystemTarget implements TargetInterface
      * Constructor
      *
      * @param string $name Name of this target instance, according to the resource settings
-     * @param array $options Options for this target
+     * @param array<string,mixed> $options Options for this target
      */
     public function __construct($name, array $options = [])
     {
@@ -217,8 +217,9 @@ public function publishCollection(CollectionInterface $collection)
         $this->checkAndRemovePackageSymlinks($storage);
         $iteration = 0;
         foreach ($collection->getObjects() as $object) {
-            $sourceStream = $object->getStream();
-            if ($sourceStream === false) {
+            try {
+                $sourceStream = $object->getStream();
+            } catch (\Exception) {
                 $this->handleMissingData($object, $collection);
                 continue;
             }
@@ -255,7 +256,7 @@ public function publishResource(PersistentResource $resource, CollectionInterfac
      * @param ResourceMetaDataInterface $resource
      * @param CollectionInterface $collection
      */
-    protected function handleMissingData(ResourceMetaDataInterface $resource, CollectionInterface $collection)
+    protected function handleMissingData(ResourceMetaDataInterface $resource, CollectionInterface $collection): void
     {
         $message = sprintf('Could not publish resource %s with SHA1 hash %s of collection %s because there seems to be no corresponding data in the storage.', $resource->getFilename(), $resource->getSha1(), $collection->getName());
         $this->messageCollector->append($message);
@@ -323,16 +324,16 @@ protected function encodeRelativePathAndFilenameForUri($relativePathAndFilename)
     protected function publishFile($sourceStream, $relativeTargetPathAndFilename)
     {
         $pathInfo = UnicodeFunctions::pathinfo($relativeTargetPathAndFilename);
-        if (isset($pathInfo['extension']) && array_key_exists(strtolower($pathInfo['extension']), $this->excludedExtensions) && $this->excludedExtensions[strtolower($pathInfo['extension'])] === true) {
-            throw new TargetException(sprintf('Could not publish "%s" into resource publishing target "%s" because the filename extension "%s" is excluded.', $sourceStream, $this->name, strtolower($pathInfo['extension'])), 1447148472);
+        if (array_key_exists(strtolower($pathInfo['extension']), $this->excludedExtensions) && $this->excludedExtensions[strtolower($pathInfo['extension'])] === true) {
+            throw new TargetException(sprintf('Could not publish resource into publishing target "%s" because the filename extension "%s" is excluded.', $this->name, strtolower($pathInfo['extension'])), 1447148472);
         }
 
         $targetPathAndFilename = $this->path . $relativeTargetPathAndFilename;
         $streamMetaData = stream_get_meta_data($sourceStream);
-        $sourcePathAndFilename = $streamMetaData['uri'] ?? null;
+        $sourcePathAndFilename = $streamMetaData['uri'];
 
         if (@fstat($sourceStream) === false) {
-            throw new TargetException(sprintf('Could not publish "%s" into resource publishing target "%s" because the source file is not accessible (file stat failed).', $sourceStream, $this->name), 1375258499);
+            throw new TargetException(sprintf('Could not publish resource into publishing target "%s" because the source file is not accessible (file stat failed).', $this->name), 1375258499);
         }
 
         // If you switch from FileSystemSymlinkTarget than we need to remove the symlink before trying to write the file
@@ -346,7 +347,7 @@ protected function publishFile($sourceStream, $relativeTargetPathAndFilename)
         }
 
         if (!is_writable(dirname($targetPathAndFilename))) {
-            throw new Exception(sprintf('Could not publish "%s" into resource publishing target "%s" because the target file "%s" is not writable.', $sourceStream, $this->name, $targetPathAndFilename), 1428917322);
+            throw new Exception(sprintf('Could not publish resource into publishing target "%s" because the target file "%s" is not writable.', $this->name, $targetPathAndFilename), 1428917322);
         }
 
         try {
@@ -361,7 +362,7 @@ protected function publishFile($sourceStream, $relativeTargetPathAndFilename)
             $result = false;
         }
         if ($result === false) {
-            throw new TargetException(sprintf('Could not publish "%s" into resource publishing target "%s" because the source file could not be copied to the target location "%s".', $sourceStream, $this->name, $targetPathAndFilename), 1375258399, ($exception ?? null));
+            throw new TargetException(sprintf('Could not publish resource into publishing target "%s" because the source file could not be copied to the target location "%s".', $this->name, $targetPathAndFilename), 1375258399, ($exception ?? null));
         }
 
         $this->logger->debug(sprintf('FileSystemTarget: Published file. (target: %s, file: %s)', $this->name, $relativeTargetPathAndFilename));
diff --git a/Neos.Flow/Classes/Security/Account.php b/Neos.Flow/Classes/Security/Account.php
index 59afe04d2f..edd33c6b55 100644
--- a/Neos.Flow/Classes/Security/Account.php
+++ b/Neos.Flow/Classes/Security/Account.php
@@ -55,7 +55,7 @@ class Account
     protected $creationDate;
 
     /**
-     * @var \DateTime
+     * @var \DateTime|null
      * @ORM\Column(nullable=true)
      */
     protected $expirationDate;
@@ -73,7 +73,7 @@ class Account
     protected $failedAuthenticationCount;
 
     /**
-     * @var array of strings
+     * @var array<string>
      * @ORM\Column(type="simple_array", nullable=true)
      */
     protected $roleIdentifiers = [];
@@ -225,9 +225,6 @@ public function setRoles(array $roles)
         $this->roleIdentifiers = [];
         $this->roles = [];
         foreach ($roles as $role) {
-            if (!$role instanceof Role) {
-                throw new \InvalidArgumentException(sprintf('setRoles() only accepts an array of %s instances, given: "%s"', Role::class, gettype($role)), 1397125997);
-            }
             $this->addRole($role);
         }
     }
@@ -310,7 +307,7 @@ public function getExpirationDate()
     /**
      * Sets the date on which this account will become inactive
      *
-     * @param \DateTime $expirationDate
+     * @param ?\DateTime $expirationDate
      * @return void
      * @api
      */
diff --git a/Neos.Flow/Classes/Security/AccountFactory.php b/Neos.Flow/Classes/Security/AccountFactory.php
index e90acf5f0f..69a62229ff 100644
--- a/Neos.Flow/Classes/Security/AccountFactory.php
+++ b/Neos.Flow/Classes/Security/AccountFactory.php
@@ -37,7 +37,7 @@ class AccountFactory
      *
      * @param string $identifier Identifier of the account, must be unique
      * @param string $password The clear text password
-     * @param array $roleIdentifiers Optionally an array of role identifiers to assign to the new account
+     * @param array<string> $roleIdentifiers Optionally an array of role identifiers to assign to the new account
      * @param string $authenticationProviderName Optional name of the authentication provider the account is affiliated with
      * @param string $passwordHashingStrategy Optional password hashing strategy to use for the password
      * @return Account A new account, not yet added to the account repository
diff --git a/Neos.Flow/Classes/Security/AccountRepository.php b/Neos.Flow/Classes/Security/AccountRepository.php
index b305695968..293274335e 100644
--- a/Neos.Flow/Classes/Security/AccountRepository.php
+++ b/Neos.Flow/Classes/Security/AccountRepository.php
@@ -30,7 +30,7 @@ class AccountRepository extends Repository
     const ENTITY_CLASSNAME = Account::class;
 
     /**
-     * @var array
+     * @var array<string,QueryInterface::ORDER_ASCENDING|QueryInterface::ORDER_DESCENDING>
      */
     protected $defaultOrderings = ['creationDate' => QueryInterface::ORDER_DESCENDING];
 
@@ -51,6 +51,9 @@ class AccountRepository extends Repository
      */
     public function remove($object): void
     {
+        if (!($object instanceof Account)) {
+            throw new \InvalidArgumentException('Can only remove account objects.', 1743961393);
+        }
         parent::remove($object);
 
         // destroy the sessions for the account to be removed
@@ -67,12 +70,14 @@ public function remove($object): void
     public function findByAccountIdentifierAndAuthenticationProviderName($accountIdentifier, $authenticationProviderName)
     {
         $query = $this->createQuery();
-        return $query->matching(
+        $result = $query->matching(
             $query->logicalAnd(
                 $query->equals('accountIdentifier', $accountIdentifier),
                 $query->equals('authenticationProviderName', $authenticationProviderName)
             )
         )->execute()->getFirst();
+
+        return $result instanceof Account ? $result : null;
     }
 
     /**
@@ -85,7 +90,7 @@ public function findByAccountIdentifierAndAuthenticationProviderName($accountIde
     public function findActiveByAccountIdentifierAndAuthenticationProviderName($accountIdentifier, $authenticationProviderName)
     {
         $query = $this->createQuery();
-        return $query->matching(
+        $result = $query->matching(
             $query->logicalAnd(
                 $query->equals('accountIdentifier', $accountIdentifier),
                 $query->equals('authenticationProviderName', $authenticationProviderName),
@@ -95,5 +100,7 @@ public function findActiveByAccountIdentifierAndAuthenticationProviderName($acco
                 )
             )
         )->execute()->getFirst();
+
+        return $result instanceof Account ? $result : null;
     }
 }
diff --git a/Neos.Flow/Classes/Security/Aspect/LoggingAspect.php b/Neos.Flow/Classes/Security/Aspect/LoggingAspect.php
index e85afc9ac1..ae4271ee8c 100644
--- a/Neos.Flow/Classes/Security/Aspect/LoggingAspect.php
+++ b/Neos.Flow/Classes/Security/Aspect/LoggingAspect.php
@@ -100,9 +100,9 @@ public function logManagerLogout(JoinPointInterface $joinPoint)
     }
 
     /**
-     * @param array $collectedIdentifiers
+     * @param array<string> $collectedIdentifiers
      * @param TokenInterface $token
-     * @return array
+     * @return array<string>
      */
     protected function reduceTokenToAccountIdentifier(array $collectedIdentifiers, TokenInterface $token): array
     {
@@ -170,7 +170,7 @@ public function logPrivilegeAccessDecisions(JoinPointInterface $joinPoint)
 
     /**
      * @param JoinPointInterface $joinPoint
-     * @return array
+     * @return array<string,array{packageKey: string, className: string, methodName: string}>
      */
     protected function getLogEnvironmentFromJoinPoint(JoinPointInterface $joinPoint): array
     {
diff --git a/Neos.Flow/Classes/Security/Authentication/AuthenticationProviderInterface.php b/Neos.Flow/Classes/Security/Authentication/AuthenticationProviderInterface.php
index 965c39a1d1..8f3dbf3b6a 100644
--- a/Neos.Flow/Classes/Security/Authentication/AuthenticationProviderInterface.php
+++ b/Neos.Flow/Classes/Security/Authentication/AuthenticationProviderInterface.php
@@ -21,7 +21,7 @@ interface AuthenticationProviderInterface
      * Constructs an instance with the given name and options.
      *
      * @param string $name
-     * @param array $options
+     * @param array<mixed> $options
      * @return self
      */
     public static function create(string $name, array $options);
@@ -37,7 +37,7 @@ public function canAuthenticate(TokenInterface $token);
     /**
      * Returns the classnames of the tokens this provider is responsible for.
      *
-     * @return array The classname of the token this provider is responsible for
+     * @return array<class-string<TokenInterface>> The classname of the token this provider is responsible for
      */
     public function getTokenClassNames();
 
diff --git a/Neos.Flow/Classes/Security/Authentication/AuthenticationProviderManager.php b/Neos.Flow/Classes/Security/Authentication/AuthenticationProviderManager.php
index ed40991eab..5746d2c08f 100644
--- a/Neos.Flow/Classes/Security/Authentication/AuthenticationProviderManager.php
+++ b/Neos.Flow/Classes/Security/Authentication/AuthenticationProviderManager.php
@@ -51,7 +51,7 @@ class AuthenticationProviderManager implements AuthenticationManagerInterface
      * Injected configuration for providers.
      * Will be null'd again after building the object instances.
      *
-     * @var array|null
+     * @var array<mixed>|null
      */
     protected $providerConfigurations;
 
@@ -81,7 +81,7 @@ public function __construct(TokenAndProviderFactoryInterface $tokenAndProviderFa
     /**
      * Inject the settings and does a fresh build of tokens based on the injected settings
      *
-     * @param array $settings The settings
+     * @param array<string,mixed> $settings The settings
      * @return void
      * @throws Exception
      */
@@ -206,7 +206,10 @@ public function isAuthenticated(): bool
             } catch (AuthenticationRequiredException $exception) {
             }
         }
-        return $this->isAuthenticated;
+
+        return $this->isAuthenticated !== null
+            ? $this->isAuthenticated
+            : false;
     }
 
     /**
diff --git a/Neos.Flow/Classes/Security/Authentication/AuthenticationProviderResolver.php b/Neos.Flow/Classes/Security/Authentication/AuthenticationProviderResolver.php
index d04def1887..30bf153f7c 100644
--- a/Neos.Flow/Classes/Security/Authentication/AuthenticationProviderResolver.php
+++ b/Neos.Flow/Classes/Security/Authentication/AuthenticationProviderResolver.php
@@ -47,12 +47,12 @@ public function __construct(ObjectManagerInterface $objectManager)
     public function resolveProviderClass($providerName)
     {
         $className = $this->objectManager->getClassNameByObjectName($providerName);
-        if ($className !== false) {
+        if ($className !== false && is_subclass_of($className, AuthenticationProviderInterface::class)) {
             return $className;
         }
 
         $className = $this->objectManager->getClassNameByObjectName('Neos\Flow\Security\Authentication\Provider\\' . $providerName);
-        if ($className !== false) {
+        if ($className !== false && is_subclass_of($className, AuthenticationProviderInterface::class)) {
             return $className;
         }
 
diff --git a/Neos.Flow/Classes/Security/Authentication/Controller/AbstractAuthenticationController.php b/Neos.Flow/Classes/Security/Authentication/Controller/AbstractAuthenticationController.php
index 0c5fe443a5..7ac7f4aae6 100644
--- a/Neos.Flow/Classes/Security/Authentication/Controller/AbstractAuthenticationController.php
+++ b/Neos.Flow/Classes/Security/Authentication/Controller/AbstractAuthenticationController.php
@@ -85,7 +85,11 @@ public function authenticateAction()
 
         if (!$this->authenticationManager->isAuthenticated()) {
             $this->onAuthenticationFailure($authenticationException);
-            return call_user_func([$this, $this->errorMethodName]);
+            $callable = [$this, $this->errorMethodName];
+            if (!is_callable($callable)) {
+                throw new \Exception('Invalid error method ' . $this->errorMethodName, 1743955562);
+            }
+            return call_user_func($callable);
         }
 
         $storedRequest = $this->securityContext->getInterceptedRequest();
diff --git a/Neos.Flow/Classes/Security/Authentication/EntryPoint/AbstractEntryPoint.php b/Neos.Flow/Classes/Security/Authentication/EntryPoint/AbstractEntryPoint.php
index f11c1d5e60..c609acbd56 100644
--- a/Neos.Flow/Classes/Security/Authentication/EntryPoint/AbstractEntryPoint.php
+++ b/Neos.Flow/Classes/Security/Authentication/EntryPoint/AbstractEntryPoint.php
@@ -21,14 +21,14 @@ abstract class AbstractEntryPoint implements EntryPointInterface
     /**
      * The configurations options
      *
-     * @var array
+     * @var array<mixed>
      */
     protected $options = [];
 
     /**
      * Sets the options array
      *
-     * @param array $options An array of configuration options
+     * @param array<mixed> $options An array of configuration options
      * @return void
      */
     public function setOptions(array $options)
@@ -39,7 +39,7 @@ public function setOptions(array $options)
     /**
      * Returns the options array
      *
-     * @return array The configuration options of this entry point
+     * @return array<mixed> The configuration options of this entry point
      */
     public function getOptions()
     {
diff --git a/Neos.Flow/Classes/Security/Authentication/EntryPoint/WebRedirect.php b/Neos.Flow/Classes/Security/Authentication/EntryPoint/WebRedirect.php
index a37757f4b0..b0aacac10c 100644
--- a/Neos.Flow/Classes/Security/Authentication/EntryPoint/WebRedirect.php
+++ b/Neos.Flow/Classes/Security/Authentication/EntryPoint/WebRedirect.php
@@ -75,7 +75,7 @@ public function startAuthentication(ServerRequestInterface $request, ResponseInt
     }
 
     /**
-     * @param array $routeValues
+     * @param array<string,mixed> $routeValues
      * @param ServerRequestInterface $request
      * @return string
      * @throws \Neos\Flow\Mvc\Routing\Exception\MissingActionNameException
@@ -96,7 +96,7 @@ protected function generateUriFromRouteValues(array $routeValues, ServerRequestI
      * Returns the entry $key from the array $routeValues removing the original array item.
      * If $key does not exist, NULL is returned.
      *
-     * @param array $routeValues
+     * @param array<string,mixed> $routeValues
      * @param string $key
      * @return mixed the specified route value or NULL if it is not set
      */
diff --git a/Neos.Flow/Classes/Security/Authentication/EntryPointInterface.php b/Neos.Flow/Classes/Security/Authentication/EntryPointInterface.php
index 9fba7eb5ac..3db795974b 100644
--- a/Neos.Flow/Classes/Security/Authentication/EntryPointInterface.php
+++ b/Neos.Flow/Classes/Security/Authentication/EntryPointInterface.php
@@ -22,7 +22,7 @@ interface EntryPointInterface
     /**
      * Sets the options array
      *
-     * @param array $options An array of configuration options
+     * @param array<mixed> $options An array of configuration options
      * @return void
      */
     public function setOptions(array $options);
@@ -30,7 +30,7 @@ public function setOptions(array $options);
     /**
      * Returns the options array
      *
-     * @return array An array of configuration options
+     * @return array<mixed> An array of configuration options
      */
     public function getOptions();
 
diff --git a/Neos.Flow/Classes/Security/Authentication/Provider/AbstractProvider.php b/Neos.Flow/Classes/Security/Authentication/Provider/AbstractProvider.php
index 7ddcac499c..c518e7bd8c 100644
--- a/Neos.Flow/Classes/Security/Authentication/Provider/AbstractProvider.php
+++ b/Neos.Flow/Classes/Security/Authentication/Provider/AbstractProvider.php
@@ -26,7 +26,7 @@ abstract class AbstractProvider implements AuthenticationProviderInterface
     protected $name;
 
     /**
-     * @var array
+     * @var array<mixed>
      */
     protected $options = [];
 
@@ -34,7 +34,7 @@ abstract class AbstractProvider implements AuthenticationProviderInterface
      * Factory method
      *
      * @param string $name
-     * @param array $options
+     * @param array<mixed> $options
      * @return AuthenticationProviderInterface
      * @api
      */
@@ -47,7 +47,7 @@ public static function create(string $name, array $options)
      * Protected constructor, see create method
      *
      * @param string $name The name of this authentication provider
-     * @param array $options Additional configuration options
+     * @param array<mixed> $options Additional configuration options
      * @see create
      */
     protected function __construct($name, array $options = [])
diff --git a/Neos.Flow/Classes/Security/Authentication/Provider/FileBasedSimpleKeyProvider.php b/Neos.Flow/Classes/Security/Authentication/Provider/FileBasedSimpleKeyProvider.php
index 5f92aa376a..14fbfff42b 100644
--- a/Neos.Flow/Classes/Security/Authentication/Provider/FileBasedSimpleKeyProvider.php
+++ b/Neos.Flow/Classes/Security/Authentication/Provider/FileBasedSimpleKeyProvider.php
@@ -66,7 +66,7 @@ class FileBasedSimpleKeyProvider extends AbstractProvider
     /**
      * Returns the class names of the tokens this provider can authenticate.
      *
-     * @return array
+     * @return array<class-string<TokenInterface>>
      */
     public function getTokenClassNames()
     {
@@ -106,7 +106,8 @@ public function authenticate(TokenInterface $authenticationToken)
      */
     protected function validateCredentials(PasswordTokenInterface $authenticationToken): void
     {
-        if (!$this->hashService->validatePassword($authenticationToken->getPassword(), $this->fileBasedSimpleKeyService->getKey($this->options['keyName']))) {
+        $key = $this->fileBasedSimpleKeyService->getKey($this->options['keyName']);
+        if (!$this->hashService->validatePassword($authenticationToken->getPassword(),$key)) {
             $authenticationToken->setAuthenticationStatus(TokenInterface::WRONG_CREDENTIALS);
             return;
         }
diff --git a/Neos.Flow/Classes/Security/Authentication/Provider/PersistedUsernamePasswordProvider.php b/Neos.Flow/Classes/Security/Authentication/Provider/PersistedUsernamePasswordProvider.php
index 4c14105b59..7861c532bc 100644
--- a/Neos.Flow/Classes/Security/Authentication/Provider/PersistedUsernamePasswordProvider.php
+++ b/Neos.Flow/Classes/Security/Authentication/Provider/PersistedUsernamePasswordProvider.php
@@ -62,7 +62,7 @@ class PersistedUsernamePasswordProvider extends AbstractProvider
     /**
      * Returns the class names of the tokens this provider can authenticate.
      *
-     * @return array
+     * @return array<class-string<TokenInterface>>
      */
     public function getTokenClassNames()
     {
diff --git a/Neos.Flow/Classes/Security/Authentication/Provider/TestingProvider.php b/Neos.Flow/Classes/Security/Authentication/Provider/TestingProvider.php
index cff0310b51..7fc46ea159 100644
--- a/Neos.Flow/Classes/Security/Authentication/Provider/TestingProvider.php
+++ b/Neos.Flow/Classes/Security/Authentication/Provider/TestingProvider.php
@@ -34,7 +34,7 @@ class TestingProvider extends AbstractProvider
     /**
      * Returns the class names of the tokens this provider can authenticate.
      *
-     * @return array
+     * @return array<class-string<TokenInterface>>
      */
     public function getTokenClassNames()
     {
diff --git a/Neos.Flow/Classes/Security/Authentication/Token/AbstractToken.php b/Neos.Flow/Classes/Security/Authentication/Token/AbstractToken.php
index 42900ce9f6..8b431a086f 100644
--- a/Neos.Flow/Classes/Security/Authentication/Token/AbstractToken.php
+++ b/Neos.Flow/Classes/Security/Authentication/Token/AbstractToken.php
@@ -36,18 +36,18 @@ abstract class AbstractToken implements TokenInterface
 
     /**
      * The credentials submitted by the client
-     * @var array
+     * @var array<mixed>
      * @Flow\Transient
      */
     protected $credentials = [];
 
     /**
-     * @var Account
+     * @var ?Account
      */
     protected $account;
 
     /**
-     * @var array
+     * @var array<RequestPatternInterface>
      */
     protected $requestPatterns = [];
 
@@ -59,14 +59,14 @@ abstract class AbstractToken implements TokenInterface
 
     /**
      * Token options
-     * @var array
+     * @var array<mixed>
      */
     protected $options;
 
     /**
      * Build an instance of this token, potentially passing it options that can be configured via `tokenOptions`
      *
-     * @param array|null $options
+     * @param array<mixed>|null $options
      */
     public function __construct(?array $options = null)
     {
@@ -138,7 +138,7 @@ public function hasRequestPatterns()
     /**
      * Sets request patterns
      *
-     * @param array $requestPatterns Array of RequestPatternInterface to be set
+     * @param array<mixed> $requestPatterns Array of RequestPatternInterface to be set
      * @return void
      * @throws \InvalidArgumentException
      */
@@ -166,7 +166,7 @@ public function getRequestPatterns()
     /**
      * Returns the credentials (username and password) of this token.
      *
-     * @return array $credentials The needed credentials to authenticate this token
+     * @return array<mixed> $credentials The needed credentials to authenticate this token
      */
     public function getCredentials()
     {
@@ -176,7 +176,7 @@ public function getCredentials()
     /**
      * Returns the account if one is authenticated, NULL otherwise.
      *
-     * @return Account An account object
+     * @return ?Account An account object
      */
     public function getAccount()
     {
@@ -186,7 +186,7 @@ public function getAccount()
     /**
      * Set the (authenticated) account
      *
-     * @param Account $account An account object
+     * @param ?Account $account An account object
      * @return void
      */
     public function setAccount(?Account $account = null)
diff --git a/Neos.Flow/Classes/Security/Authentication/Token/BearerToken.php b/Neos.Flow/Classes/Security/Authentication/Token/BearerToken.php
index e51e3960ef..f09688a55a 100644
--- a/Neos.Flow/Classes/Security/Authentication/Token/BearerToken.php
+++ b/Neos.Flow/Classes/Security/Authentication/Token/BearerToken.php
@@ -30,7 +30,7 @@ class BearerToken extends AbstractToken implements SessionlessTokenInterface
 {
     /**
      * The password credentials
-     * @var array
+     * @var array{bearer: string}
      * @Flow\Transient
      */
     protected $credentials = ['bearer' => ''];
diff --git a/Neos.Flow/Classes/Security/Authentication/Token/PasswordToken.php b/Neos.Flow/Classes/Security/Authentication/Token/PasswordToken.php
index 90732a5ec1..2ecfaf9bbb 100644
--- a/Neos.Flow/Classes/Security/Authentication/Token/PasswordToken.php
+++ b/Neos.Flow/Classes/Security/Authentication/Token/PasswordToken.php
@@ -25,7 +25,7 @@ class PasswordToken extends AbstractToken implements PasswordTokenInterface
 
     /**
      * The password credentials
-     * @var array
+     * @var array{password: string,}
      * @Flow\Transient
      */
     protected $credentials = ['password' => ''];
@@ -60,7 +60,7 @@ public function updateCredentials(ActionRequest $actionRequest)
      */
     public function getPassword(): string
     {
-        return $this->credentials['password'] ?? '';
+        return $this->credentials['password'];
     }
 
     /**
diff --git a/Neos.Flow/Classes/Security/Authentication/Token/UsernamePassword.php b/Neos.Flow/Classes/Security/Authentication/Token/UsernamePassword.php
index 657ee6627d..5c93accc5e 100644
--- a/Neos.Flow/Classes/Security/Authentication/Token/UsernamePassword.php
+++ b/Neos.Flow/Classes/Security/Authentication/Token/UsernamePassword.php
@@ -26,7 +26,7 @@ class UsernamePassword extends AbstractToken implements UsernamePasswordTokenInt
 
     /**
      * The username/password credentials
-     * @var array
+     * @var array{username: string, password: string,}
      * @Flow\Transient
      */
     protected $credentials = ['username' => '', 'password' => ''];
@@ -78,7 +78,7 @@ public function updateCredentials(ActionRequest $actionRequest)
      */
     public function getUsername(): string
     {
-        return $this->credentials['username'] ?? '';
+        return $this->credentials['username'];
     }
 
     /**
@@ -86,7 +86,7 @@ public function getUsername(): string
      */
     public function getPassword(): string
     {
-        return $this->credentials['password'] ?? '';
+        return $this->credentials['password'];
     }
 
     /**
diff --git a/Neos.Flow/Classes/Security/Authentication/Token/UsernamePasswordHttpBasic.php b/Neos.Flow/Classes/Security/Authentication/Token/UsernamePasswordHttpBasic.php
index f8095bae8c..5342185072 100644
--- a/Neos.Flow/Classes/Security/Authentication/Token/UsernamePasswordHttpBasic.php
+++ b/Neos.Flow/Classes/Security/Authentication/Token/UsernamePasswordHttpBasic.php
@@ -28,7 +28,7 @@ class UsernamePasswordHttpBasic extends UsernamePassword implements SessionlessT
      */
     public function updateCredentials(ActionRequest $actionRequest)
     {
-        $this->credentials = ['username' => null, 'password' => null];
+        $this->credentials = ['username' => '', 'password' => ''];
         $this->authenticationStatus = self::NO_CREDENTIALS_GIVEN;
 
         $authorizationHeader = $actionRequest->getHttpRequest()->getHeaderLine('Authorization');
diff --git a/Neos.Flow/Classes/Security/Authentication/TokenAndProviderFactory.php b/Neos.Flow/Classes/Security/Authentication/TokenAndProviderFactory.php
index 4fe716176e..0314714fe5 100644
--- a/Neos.Flow/Classes/Security/Authentication/TokenAndProviderFactory.php
+++ b/Neos.Flow/Classes/Security/Authentication/TokenAndProviderFactory.php
@@ -40,7 +40,7 @@ class TokenAndProviderFactory implements TokenAndProviderFactoryInterface
     protected $tokens = [];
 
     /**
-     * @var array
+     * @var array<string,array<mixed>>
      */
     protected $providerConfigurations = [];
 
@@ -113,7 +113,7 @@ public function getProviders(): array
     /**
      * Inject the settings and does a fresh build of tokens based on the injected settings
      *
-     * @param array $settings The settings
+     * @param array<string,mixed> $settings The settings
      * @return void
      * @throws Exception
      */
@@ -151,14 +151,11 @@ protected function buildProvidersAndTokensFromConfiguration()
                 continue;
             }
 
-            if (!is_array($providerConfiguration) || !isset($providerConfiguration['provider'])) {
+            if (!isset($providerConfiguration['provider'])) {
                 throw new Exception\InvalidAuthenticationProviderException('The configured authentication provider "' . $providerName . '" needs a "provider" option!', 1248209521);
             }
 
             $providerObjectName = $this->providerResolver->resolveProviderClass((string)$providerConfiguration['provider']);
-            if ($providerObjectName === null) {
-                throw new Exception\InvalidAuthenticationProviderException('The configured authentication provider "' . $providerConfiguration['provider'] . '" could not be found!', 1237330453);
-            }
             $providerOptions = [];
             if (isset($providerConfiguration['providerOptions']) && is_array($providerConfiguration['providerOptions'])) {
                 $providerOptions = $providerConfiguration['providerOptions'];
@@ -175,7 +172,7 @@ protected function buildProvidersAndTokensFromConfiguration()
                 }
                 $tokenInstance = $this->objectManager->get($tokenClassName, $providerConfiguration['tokenOptions'] ?? []);
                 if (!$tokenInstance instanceof TokenInterface) {
-                    throw new Exception\InvalidAuthenticationProviderException(sprintf('The specified token is not an instance of %s but a %s. Please adjust the "token" configuration of the "%s" authentication provider', TokenInterface::class, is_object($tokenInstance) ? get_class($tokenInstance) : gettype($tokenInstance), $providerName), 1585921152);
+                    throw new Exception\InvalidAuthenticationProviderException(sprintf('The specified token is not an instance of %s but a %s. Please adjust the "token" configuration of the "%s" authentication provider', TokenInterface::class, get_class($tokenInstance), $providerName), 1585921152);
                 }
                 $tokenInstance->setAuthenticationProviderName($providerName);
                 $this->tokens[] = $tokenInstance;
@@ -225,7 +222,7 @@ protected function buildProvidersAndTokensFromConfiguration()
                     $entryPoint->setOptions($providerConfiguration['entryPointOptions']);
                 }
 
-                $tokenInstance->setAuthenticationEntryPoint($entryPoint);
+                $tokenInstance?->setAuthenticationEntryPoint($entryPoint);
             }
         }
 
diff --git a/Neos.Flow/Classes/Security/Authentication/TokenInterface.php b/Neos.Flow/Classes/Security/Authentication/TokenInterface.php
index 13b6eb868c..da0f6c96f4 100644
--- a/Neos.Flow/Classes/Security/Authentication/TokenInterface.php
+++ b/Neos.Flow/Classes/Security/Authentication/TokenInterface.php
@@ -102,7 +102,7 @@ public function hasRequestPatterns();
     /**
      * Sets request patterns
      *
-     * @param array $requestPatterns Array of \Neos\Flow\Security\RequestPatternInterface to be set
+     * @param array<RequestPatternInterface> $requestPatterns Array of \Neos\Flow\Security\RequestPatternInterface to be set
      * @return void
      * @see hasRequestPattern()
      */
@@ -139,14 +139,14 @@ public function getCredentials();
     /**
      * Returns the account if one is authenticated, NULL otherwise.
      *
-     * @return Account An account object
+     * @return ?Account An account object
      */
     public function getAccount();
 
     /**
      * Set the (authenticated) account
      *
-     * @param Account $account An account object
+     * @param ?Account $account An account object
      * @return void
      */
     public function setAccount(?Account $account = null);
diff --git a/Neos.Flow/Classes/Security/Authorization/FilterFirewall.php b/Neos.Flow/Classes/Security/Authorization/FilterFirewall.php
index 1d2bc80d53..1798c1e927 100644
--- a/Neos.Flow/Classes/Security/Authorization/FilterFirewall.php
+++ b/Neos.Flow/Classes/Security/Authorization/FilterFirewall.php
@@ -72,7 +72,7 @@ public function __construct(
     /**
      * Injects the configuration settings
      *
-     * @param array $settings
+     * @param array<string,mixed> $settings
      * @return void
      */
     public function injectSettings(array $settings)
@@ -101,7 +101,7 @@ public function blockIllegalRequests(ActionRequest $request)
     }
 
     /**
-     * @param array $filterConfiguration
+     * @param array<string,mixed> $filterConfiguration
      * @return RequestFilter
      * @throws \Neos\Flow\Security\Exception\NoInterceptorFoundException
      * @throws \Neos\Flow\Security\Exception\NoRequestPatternFoundException
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/ConjunctionGenerator.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/ConjunctionGenerator.php
index 6a4d46cdce..56bdbf7aa0 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/ConjunctionGenerator.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/ConjunctionGenerator.php
@@ -11,7 +11,7 @@
  * source code.
  */
 
-use Doctrine\Persistence\Mapping\ClassMetadata;
+use Doctrine\ORM\Mapping\ClassMetadata;
 use Doctrine\ORM\Query\Filter\SQLFilter as DoctrineSqlFilter;
 use Neos\Flow\Annotations as Flow;
 
@@ -35,14 +35,13 @@ public function __construct(array $expressions)
 
     /**
      * @param DoctrineSqlFilter $sqlFilter
-     * @param ClassMetadata $targetEntity Metadata object for the target entity to create the constraint for
+     * @param ClassMetadata<object> $targetEntity Metadata object for the target entity to create the constraint for
      * @param string $targetTableAlias The target table alias used in the current query
      * @return string
      */
     public function getSql(DoctrineSqlFilter $sqlFilter, ClassMetadata $targetEntity, $targetTableAlias)
     {
         $sql = '';
-        /** @var SqlGeneratorInterface $expression */
         foreach ($this->expressions as $expression) {
             $sql .= ($sql !== '' ? ' AND ' : '') . $expression->getSql($sqlFilter, $targetEntity, $targetTableAlias);
         }
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/DisjunctionGenerator.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/DisjunctionGenerator.php
index dafb1dfa59..c40043681e 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/DisjunctionGenerator.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/DisjunctionGenerator.php
@@ -11,7 +11,7 @@
  * source code.
  */
 
-use Doctrine\Persistence\Mapping\ClassMetadata;
+use Doctrine\ORM\Mapping\ClassMetadata;
 use Doctrine\ORM\Query\Filter\SQLFilter as DoctrineSqlFilter;
 use Neos\Flow\Annotations as Flow;
 
@@ -35,14 +35,13 @@ public function __construct(array $expressions)
 
     /**
      * @param DoctrineSqlFilter $sqlFilter
-     * @param ClassMetaData $targetEntity Metadata object for the target entity to create the constraint for
+     * @param ClassMetaData<object> $targetEntity Metadata object for the target entity to create the constraint for
      * @param string $targetTableAlias The target table alias used in the current query
      * @return string
      */
     public function getSql(DoctrineSqlFilter $sqlFilter, ClassMetadata $targetEntity, $targetTableAlias)
     {
         $sql = '';
-        /** @var SqlGeneratorInterface $expression */
         foreach ($this->expressions as $expression) {
             $sql .= ($sql !== '' ? ' OR ' : '') . $expression->getSql($sqlFilter, $targetEntity, $targetTableAlias);
         }
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/EntityPrivilege.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/EntityPrivilege.php
index 732aa8fade..ef39203a50 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/EntityPrivilege.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/EntityPrivilege.php
@@ -60,11 +60,11 @@ public function matchesEntityType($entityType)
     /**
      * Note: The result of this method cannot be cached, as the target table alias might change for different query scenarios
      *
-     * @param ClassMetadata $targetEntity
+     * @param \Doctrine\ORM\Mapping\ClassMetadata<object> $targetEntity
      * @param string $targetTableAlias
      * @return string|null
      */
-    public function getSqlConstraint(ClassMetadata $targetEntity, $targetTableAlias)
+    public function getSqlConstraint(\Doctrine\ORM\Mapping\ClassMetadata $targetEntity, $targetTableAlias)
     {
         $this->evaluateMatcher();
 
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/EntityPrivilegeExpressionParser.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/EntityPrivilegeExpressionParser.php
index 4e9bf53e01..b97fafc83e 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/EntityPrivilegeExpressionParser.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/EntityPrivilegeExpressionParser.php
@@ -23,10 +23,10 @@
 class EntityPrivilegeExpressionParser extends CompilingEelParser
 {
     /**
-     * @param array $result
-     * @param array $sub
+     * @param array<string,mixed> $result
+     * @param array<string,mixed> $sub
      */
-    public function NotExpression_exp(&$result, $sub)
+    public function NotExpression_exp(&$result, $sub): void
     {
         if (!isset($result['code'])) {
             $result['code'] = '$context';
@@ -35,29 +35,29 @@ public function NotExpression_exp(&$result, $sub)
     }
 
     /**
-     * @param array $result
-     * @param array $sub
+     * @param array<string,mixed> $result
+     * @param array<string,mixed> $sub
      */
-    public function Disjunction_rgt(&$result, $sub)
+    public function Disjunction_rgt(&$result, $sub): void
     {
         $result['code'] = '$context->callAndWrap(\'disjunction\', array(' . $this->unwrapExpression($result['code']) . ', ' . $this->unwrapExpression($sub['code']) . '))';
     }
 
     /**
-     * @param array $result
-     * @param array $sub
+     * @param array<string,mixed> $result
+     * @param array<string,mixed> $sub
      */
-    public function Conjunction_rgt(&$result, $sub)
+    public function Conjunction_rgt(&$result, $sub): void
     {
         $result['code'] = '$context->callAndWrap(\'conjunction\', array(' . $this->unwrapExpression($result['code']) . ', ' . $this->unwrapExpression($sub['code']) . '))';
     }
 
     /**
-     * @param array $result
-     * @param array $sub
+     * @param array<string,mixed> $result
+     * @param array<string,mixed> $sub
      * @throws ParserException
      */
-    public function Comparison_rgt(&$result, $sub)
+    public function Comparison_rgt(&$result, $sub): void
     {
         $lval = $result['code'];
         $rval = $sub['code'];
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/FalseConditionGenerator.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/FalseConditionGenerator.php
index 6fa1e62d70..abd63bf8ff 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/FalseConditionGenerator.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/FalseConditionGenerator.php
@@ -24,7 +24,7 @@ class FalseConditionGenerator implements SqlGeneratorInterface
      * Returns an SQL query part that is basically a no-op in order to match no entity
      *
      * @param DoctrineSqlFilter $sqlFilter
-     * @param ClassMetadata $targetEntity
+     * @param ClassMetadata<object> $targetEntity
      * @param string $targetTableAlias
      * @return string
      */
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/NotExpressionGenerator.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/NotExpressionGenerator.php
index 5d52747678..5bbcc1921e 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/NotExpressionGenerator.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/NotExpressionGenerator.php
@@ -11,7 +11,7 @@
  * source code.
  */
 
-use Doctrine\Persistence\Mapping\ClassMetadata;
+use Doctrine\ORM\Mapping\ClassMetadata;
 use Doctrine\ORM\Query\Filter\SQLFilter as DoctrineSqlFilter;
 use Neos\Flow\Annotations as Flow;
 
@@ -35,7 +35,7 @@ public function __construct(SqlGeneratorInterface $expression)
 
     /**
      * @param DoctrineSqlFilter $sqlFilter
-     * @param ClassMetaData $targetEntity Metadata object for the target entity to create the constraint for
+     * @param ClassMetaData<object> $targetEntity Metadata object for the target entity to create the constraint for
      * @param string $targetTableAlias The target table alias used in the current query
      * @return string
      */
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/PropertyConditionGenerator.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/PropertyConditionGenerator.php
index 7df14fff9c..7d5de3f354 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/PropertyConditionGenerator.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/PropertyConditionGenerator.php
@@ -11,7 +11,7 @@
  * source code.
  */
 
-use Doctrine\ORM\Mapping\ClassMetadataInfo;
+use Doctrine\ORM\Mapping\ClassMetadata as ORMClassMetadata;
 use Doctrine\Persistence\Mapping\ClassMetadata;
 use Doctrine\ORM\EntityManagerInterface;
 use Doctrine\ORM\Mapping\QuoteStrategy;
@@ -45,7 +45,7 @@ class PropertyConditionGenerator implements SqlGeneratorInterface
     protected $operator;
 
     /**
-     * @var string|array
+     * @var string|array<string,string|object|null>
      */
     protected $operandDefinition;
 
@@ -58,7 +58,7 @@ class PropertyConditionGenerator implements SqlGeneratorInterface
      * Array of registered global objects that can be accessed as operands
      *
      * @Flow\InjectConfiguration("aop.globalObjects")
-     * @var array
+     * @var array<string,string>
      */
     protected $globalObjects = [];
 
@@ -95,7 +95,7 @@ class PropertyConditionGenerator implements SqlGeneratorInterface
     /**
      * Raw parameter values
      *
-     * @var array
+     * @var array<mixed>
      */
     protected $parameters = [];
 
@@ -108,7 +108,7 @@ public function __construct($path)
     }
 
     /**
-     * @param string|array $operandDefinition
+     * @param string|array<string> $operandDefinition
      * @return PropertyConditionGenerator the current instance to allow for method chaining
      */
     public function equals($operandDefinition)
@@ -120,7 +120,7 @@ public function equals($operandDefinition)
     }
 
     /**
-     * @param string|array $operandDefinition
+     * @param string|array<string> $operandDefinition
      * @return PropertyConditionGenerator the current instance to allow for method chaining
      */
     public function notEquals($operandDefinition)
@@ -204,6 +204,9 @@ public function in($operandDefinition)
         if (is_array($this->operand) === false && ($this->operand instanceof \Traversable) === false) {
             throw new InvalidPolicyException(sprintf('The "in" operator needs an array as operand! Got: "%s"', $this->operand), 1416313526);
         }
+        if (!is_array($this->operandDefinition)) {
+            throw new \Exception('Cannot assign iterable operands to non-array operand definition', 1743959938);
+        }
         foreach ($this->operand as $iterator => $singleOperandValueDefinition) {
             $this->operandDefinition['inOperandValue' . $iterator] = $singleOperandValueDefinition;
         }
@@ -230,15 +233,16 @@ public function contains($operandDefinition): PropertyConditionGenerator
 
     /**
      * @param DoctrineSqlFilter $sqlFilter
-     * @param ClassMetadata $targetEntity
+     * @param ORMClassMetadata<object> $targetEntity
      * @param string $targetTableAlias
      * @return string
      * @throws InvalidQueryRewritingConstraintException
      * @throws \Exception
      */
-    public function getSql(DoctrineSqlFilter $sqlFilter, ClassMetadata $targetEntity, $targetTableAlias)
+    public function getSql(DoctrineSqlFilter $sqlFilter, ORMClassMetadata $targetEntity, $targetTableAlias)
     {
-        $targetEntityPropertyName = (strpos($this->path, '.') ? substr($this->path, 0, strpos($this->path, '.')) : $this->path);
+        $pivot = strpos($this->path, '.');
+        $targetEntityPropertyName = ($pivot ? substr($this->path, 0, $pivot) : $this->path);
         $quoteStrategy = $this->entityManager->getConfiguration()->getQuoteStrategy();
 
         if ($targetEntity->hasAssociation($targetEntityPropertyName) === false) {
@@ -248,7 +252,11 @@ public function getSql(DoctrineSqlFilter $sqlFilter, ClassMetadata $targetEntity
         } elseif ($targetEntity->isSingleValuedAssociation($targetEntityPropertyName) === true && $targetEntity->isAssociationInverseSide($targetEntityPropertyName) === false) {
             return $this->getSqlForManyToOneAndOneToOneRelationsWithPropertyPath($sqlFilter, $quoteStrategy, $targetEntity, $targetTableAlias, $targetEntityPropertyName);
         } elseif ($targetEntity->isSingleValuedAssociation($targetEntityPropertyName) === true && $targetEntity->isAssociationInverseSide($targetEntityPropertyName) === true) {
-            throw new InvalidQueryRewritingConstraintException('Single valued properties from the inverse side are not supported in a content security constraint path! Got: "' . $this->path . ' ' . $this->operator . ' ' . $this->operandDefinition . '"', 1416397754);
+            throw new InvalidQueryRewritingConstraintException(
+                'Single valued properties from the inverse side are not supported in a content security constraint path! Got: "'
+                    . $this->path . ' ' . $this->operator . ' ' . json_encode($this->operandDefinition) . '"'
+                , 1416397754
+            );
         } elseif ($targetEntity->isCollectionValuedAssociation($targetEntityPropertyName) === true) {
             return $this->getSqlForPropertyContains($sqlFilter, $quoteStrategy, $targetEntity, $targetTableAlias, $targetEntityPropertyName);
         }
@@ -259,17 +267,21 @@ public function getSql(DoctrineSqlFilter $sqlFilter, ClassMetadata $targetEntity
     /**
      * @param DoctrineSqlFilter $sqlFilter
      * @param QuoteStrategy $quoteStrategy
-     * @param ClassMetadataInfo $targetEntity
+     * @param ORMClassMetadata<object> $targetEntity
      * @param string $targetTableAlias
      * @param string $targetEntityPropertyName
      * @return string
      * @throws InvalidQueryRewritingConstraintException
      * @throws \Exception
      */
-    protected function getSqlForPropertyContains(DoctrineSqlFilter $sqlFilter, QuoteStrategy $quoteStrategy, ClassMetadata $targetEntity, string $targetTableAlias, string $targetEntityPropertyName): string
+    protected function getSqlForPropertyContains(DoctrineSqlFilter $sqlFilter, QuoteStrategy $quoteStrategy, ORMClassMetadata $targetEntity, string $targetTableAlias, string $targetEntityPropertyName): string
     {
         if ($this->operator !== 'contains') {
-            throw new InvalidQueryRewritingConstraintException('Multivalued properties are not supported in a content security constraint path unless the "contains" operation is used! Got: "' . $this->path . ' ' . $this->operator . ' ' . $this->operandDefinition . '"', 1416397655);
+            throw new InvalidQueryRewritingConstraintException(
+                'Multivalued properties are not supported in a content security constraint path unless the "contains" operation is used! Got: "'
+                    . $this->path . ' ' . $this->operator . ' ' . json_encode($this->operandDefinition) . '"',
+                1416397655
+            );
         }
 
         if (is_array($this->operandDefinition)) {
@@ -303,9 +315,6 @@ protected function getSqlForPropertyContains(DoctrineSqlFilter $sqlFilter, Quote
             $subQuerySql = 'SELECT ' . $reverseColumn . ' FROM ' . $associationMapping['joinTable']['name'] . ' WHERE ' . $joinColumn . ' = ' . $parameterValue;
         } else {
             $associationTargetClass = $targetEntity->getAssociationTargetClass($targetEntityPropertyName);
-            if ($associationTargetClass === null) {
-                throw new \InvalidArgumentException("Association name expected, '" . $targetEntityPropertyName . "' is not an association.", 1629871077);
-            }
             $subselectQuery = new Query($associationTargetClass);
             $rootAliases = $subselectQuery->getQueryBuilder()->getRootAliases();
             $primaryRootAlias = reset($rootAliases);
@@ -314,6 +323,9 @@ protected function getSqlForPropertyContains(DoctrineSqlFilter $sqlFilter, Quote
             $subselectQuery->getQueryBuilder()->select('IDENTITY(' . $primaryRootAlias . '.' . $associationMapping['mappedBy'] . ')');
             $subQuerySql = $subselectQuery->getSql();
         }
+        if (is_array($subQuerySql)) {
+            throw new \Exception('invalid sub query, must not be an array', 1743931303);
+        }
 
         return $targetTableAlias . '.' . $identityColumnName . ' IN (' . $subQuerySql . ')';
     }
@@ -321,14 +333,14 @@ protected function getSqlForPropertyContains(DoctrineSqlFilter $sqlFilter, Quote
     /**
      * @param DoctrineSqlFilter $sqlFilter
      * @param QuoteStrategy $quoteStrategy
-     * @param ClassMetadata $targetEntity
+     * @param ORMClassMetadata<object> $targetEntity
      * @param string $targetTableAlias
      * @param string $targetEntityPropertyName
      * @return string
      * @throws InvalidQueryRewritingConstraintException
      * @throws \Exception
      */
-    protected function getSqlForSimpleProperty(DoctrineSqlFilter $sqlFilter, QuoteStrategy $quoteStrategy, ClassMetadata $targetEntity, $targetTableAlias, $targetEntityPropertyName)
+    protected function getSqlForSimpleProperty(DoctrineSqlFilter $sqlFilter, QuoteStrategy $quoteStrategy, ORMClassMetadata $targetEntity, $targetTableAlias, $targetEntityPropertyName)
     {
         $quotedColumnName = $quoteStrategy->getColumnName($targetEntityPropertyName, $targetEntity, $this->entityManager->getConnection()->getDatabasePlatform());
         $propertyPointer = $targetTableAlias . '.' . $quotedColumnName;
@@ -346,35 +358,37 @@ protected function getSqlForSimpleProperty(DoctrineSqlFilter $sqlFilter, QuoteSt
     /**
      * @param DoctrineSqlFilter $sqlFilter
      * @param QuoteStrategy $quoteStrategy
-     * @param ClassMetadataInfo $targetEntity
+     * @param ORMClassMetadata<object> $targetEntity
      * @param string $targetTableAlias
      * @param string $targetEntityPropertyName
      * @return string
      * @throws InvalidQueryRewritingConstraintException
      * @throws \Exception
      */
-    protected function getSqlForManyToOneAndOneToOneRelationsWithoutPropertyPath(DoctrineSqlFilter $sqlFilter, QuoteStrategy $quoteStrategy, ClassMetadata $targetEntity, $targetTableAlias, $targetEntityPropertyName)
+    protected function getSqlForManyToOneAndOneToOneRelationsWithoutPropertyPath(DoctrineSqlFilter $sqlFilter, QuoteStrategy $quoteStrategy, ORMClassMetadata $targetEntity, $targetTableAlias, $targetEntityPropertyName)
     {
         $associationMapping = $targetEntity->getAssociationMapping($targetEntityPropertyName);
 
         $constraints = [];
-        foreach ($associationMapping['joinColumns'] as $joinColumn) {
+        foreach ($associationMapping['joinColumns'] ?? [] as $joinColumn) {
             $quotedColumnName = $quoteStrategy->getJoinColumnName($joinColumn, $targetEntity, $this->entityManager->getConnection()->getDatabasePlatform());
             $propertyPointer = $targetTableAlias . '.' . $quotedColumnName;
 
-            $operandAlias = $this->operandDefinition;
-            if (is_array($this->operandDefinition)) {
-                $operandAlias = key($this->operandDefinition);
-            }
+            $operandAlias = is_array($this->operandDefinition)
+                ? key($this->operandDefinition)
+                : $this->operandDefinition;
+
             $currentReferencedOperandName = $operandAlias . $joinColumn['referencedColumnName'];
             if (is_object($this->operand)) {
-                $operandMetadataInfo = $this->entityManager->getClassMetadata(TypeHandling::getTypeForValue($this->operand));
+                $type = TypeHandling::getTypeForValue($this->operand);
+                $operandMetadataInfo = $this->entityManager->getClassMetadata($type);
                 $currentReferencedValueOfOperand = $operandMetadataInfo->getFieldValue($this->operand, $operandMetadataInfo->getFieldForColumn($joinColumn['referencedColumnName']));
                 $this->setParameter($sqlFilter, $currentReferencedOperandName, $currentReferencedValueOfOperand, $associationMapping['type']);
             } elseif (is_array($this->operandDefinition)) {
                 foreach ($this->operandDefinition as $operandIterator => $singleOperandValue) {
                     if (is_object($singleOperandValue)) {
-                        $operandMetadataInfo = $this->entityManager->getClassMetadata(TypeHandling::getTypeForValue($singleOperandValue));
+                        $type = TypeHandling::getTypeForValue($singleOperandValue);
+                        $operandMetadataInfo = $this->entityManager->getClassMetadata($type);
                         $currentReferencedValueOfOperand = $operandMetadataInfo->getFieldValue($singleOperandValue, $operandMetadataInfo->getFieldForColumn($joinColumn['referencedColumnName']));
                         $this->setParameter($sqlFilter, $operandIterator, $currentReferencedValueOfOperand, $associationMapping['type']);
                     } elseif ($singleOperandValue === null) {
@@ -391,7 +405,7 @@ protected function getSqlForManyToOneAndOneToOneRelationsWithoutPropertyPath(Doc
     /**
      * @param DoctrineSqlFilter $sqlFilter
      * @param QuoteStrategy $quoteStrategy
-     * @param ClassMetadataInfo $targetEntity
+     * @param ORMClassMetadata<object> $targetEntity
      * @param string $targetTableAlias
      * @param string $targetEntityPropertyName
      * @return string
@@ -405,19 +419,22 @@ protected function getSqlForManyToOneAndOneToOneRelationsWithPropertyPath(Doctri
         $associationMapping = $targetEntity->getAssociationMapping($targetEntityPropertyName);
 
         $subselectConstraintQueries = [];
-        foreach ($associationMapping['joinColumns'] as $joinColumn) {
+        foreach ($associationMapping['joinColumns'] ?? [] as $joinColumn) {
             $rootAliases = $subselectQuery->getQueryBuilder()->getRootAliases();
             $subselectQuery->getQueryBuilder()->select($rootAliases[0] . '.' . $targetEntity->getFieldForColumn($joinColumn['referencedColumnName']));
             $subselectSql = $subselectQuery->getSql();
+            if (is_array($subselectSql)) {
+                $subselectSql = implode(' ', $subselectSql);
+            }
             foreach ($subselectQuery->getParameters() as $parameter) {
                 $parameterValue = $parameter->getValue();
                 if (is_object($parameterValue)) {
                     $parameterValue = $this->persistenceManager->getIdentifierByObject($parameter->getValue());
                 }
-                $subselectSql = preg_replace('/\?/', $this->entityManager->getConnection()->quote($parameterValue, $parameter->getType()), $subselectSql, 1);
+                $subselectSql = preg_replace('/\?/', $this->entityManager->getConnection()->quote($parameterValue, $parameter->getType()), $subselectSql ?: '', 1);
             }
             $quotedColumnName = $quoteStrategy->getJoinColumnName($joinColumn, $targetEntity, $this->entityManager->getConnection()->getDatabasePlatform());
-            $subselectIdentifier = 'subselect' . md5($subselectSql);
+            $subselectIdentifier = 'subselect' . md5($subselectSql ?: '');
             $subselectConstraintQueries[] = $targetTableAlias . '.' . $quotedColumnName . ' IN (SELECT ' . $subselectIdentifier . '.' . $joinColumn['referencedColumnName'] . '_0 FROM (' . $subselectSql . ') AS ' . $subselectIdentifier . ' ) ';
         }
 
@@ -425,7 +442,7 @@ protected function getSqlForManyToOneAndOneToOneRelationsWithPropertyPath(Doctri
     }
 
     /**
-     * @param ClassMetadata $targetEntity
+     * @param ClassMetadata<object> $targetEntity
      * @param string $targetEntityPropertyName
      * @return Query
      */
@@ -494,6 +511,9 @@ protected function getConstraintStringForSimpleProperty(DoctrineSqlFilter $sqlFi
                 }
                 $parameter = implode(',', $parameters);
             } elseif (!($this->getRawParameterValue($operandDefinition) === null || ($this->operator === 'in' && $this->getRawParameterValue($operandDefinition) === []))) {
+                if (!is_string($operandDefinition)) {
+                    throw new \Exception('SQL filter parameters must be of type string, ' . get_debug_type($operandDefinition) . ' given.', 1743929393);
+                }
                 $parameter = $sqlFilter->getParameter($operandDefinition);
             }
         } catch (\InvalidArgumentException $exception) {
@@ -567,11 +587,12 @@ public function getValueForOperand($expression)
      * @param DoctrineSqlFilter $sqlFilter
      * @param mixed $name
      * @param mixed $value
-     * @param string $type
+     * @param string|int|null $type
      * @return void
      */
     protected function setParameter(DoctrineSqlFilter $sqlFilter, $name, $value, $type = null)
     {
+        /** @phpstan-ignore argument.type (currently, doctrine also can handle integers) */
         $sqlFilter->setParameter($name, $value, $type);
         $this->parameters[$name] = $value;
     }
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/SqlFilter.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/SqlFilter.php
index e43d3f70d2..e83fb7d40e 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/SqlFilter.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/SqlFilter.php
@@ -40,7 +40,7 @@ class SqlFilter extends DoctrineSqlFilter
     /**
      * Gets the SQL query part to add to a query.
      *
-     * @param ClassMetadata $targetEntity Metadata object for the target entity to be filtered
+     * @param ClassMetadata<object> $targetEntity Metadata object for the target entity to be filtered
      * @param string $targetTableAlias The target table alias used in the current query
      * @return string The constraint SQL if there is available, empty string otherwise
      */
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/SqlGeneratorInterface.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/SqlGeneratorInterface.php
index 6f096aec14..c061488576 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/SqlGeneratorInterface.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/SqlGeneratorInterface.php
@@ -11,7 +11,7 @@
  * source code.
  */
 
-use Doctrine\Persistence\Mapping\ClassMetadata;
+use Doctrine\ORM\Mapping\ClassMetadata;
 use Doctrine\ORM\Query\Filter\SQLFilter as DoctrineSqlFilter;
 use Neos\Flow\Annotations as Flow;
 
@@ -22,7 +22,7 @@ interface SqlGeneratorInterface
 {
     /**
      * @param DoctrineSqlFilter $sqlFilter
-     * @param ClassMetadata $targetEntity Metadata object for the target entity to create the constraint for
+     * @param ClassMetadata<object> $targetEntity Metadata object for the target entity to create the constraint for
      * @param string $targetTableAlias The target table alias used in the current query
      * @return string
      */
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/TrueConditionGenerator.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/TrueConditionGenerator.php
index 71f5b97f95..68fd7e4e8a 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/TrueConditionGenerator.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/Doctrine/TrueConditionGenerator.php
@@ -24,7 +24,7 @@ class TrueConditionGenerator implements SqlGeneratorInterface
      * Returns an SQL query part that is basically a no-op in order to match any entity
      *
      * @param DoctrineSqlFilter $sqlFilter
-     * @param ClassMetadata $targetEntity
+     * @param ClassMetadata<object> $targetEntity
      * @param string $targetTableAlias
      * @return string
      */
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/EntityPrivilegeInterface.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/EntityPrivilegeInterface.php
index e9dab06ce2..096207a62b 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/EntityPrivilegeInterface.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Entity/EntityPrivilegeInterface.php
@@ -11,7 +11,7 @@
  * source code.
  */
 
-use Doctrine\Persistence\Mapping\ClassMetadata;
+use Doctrine\ORM\Mapping\ClassMetadata;
 use Neos\Flow\Annotations as Flow;
 use Neos\Flow\Security\Authorization\Privilege\PrivilegeInterface;
 
@@ -32,9 +32,9 @@ interface EntityPrivilegeInterface extends PrivilegeInterface
     public function matchesEntityType($entityType);
 
     /**
-     * @param ClassMetadata $targetEntity
+     * @param ClassMetadata<object> $targetEntity
      * @param string $targetTableAlias
-     * @return string
+     * @return string|null
      */
     public function getSqlConstraint(ClassMetadata $targetEntity, $targetTableAlias);
 }
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Method/MethodPrivilege.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Method/MethodPrivilege.php
index 8bed00aa93..aa8d2fb262 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Method/MethodPrivilege.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Method/MethodPrivilege.php
@@ -27,7 +27,7 @@
 class MethodPrivilege extends AbstractPrivilege implements MethodPrivilegeInterface
 {
     /**
-     * @var array
+     * @var array<string,array<string,array<string,mixed>>>
      */
     protected static $methodPermissions;
 
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Method/MethodPrivilegePointcutFilter.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Method/MethodPrivilegePointcutFilter.php
index b0887246b0..2fd52aa85c 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Method/MethodPrivilegePointcutFilter.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Method/MethodPrivilegePointcutFilter.php
@@ -34,7 +34,7 @@ class MethodPrivilegePointcutFilter implements PointcutFilterInterface
     protected $filters = null;
 
     /**
-     * @var array
+     * @var array<mixed>
      */
     protected $methodPermissions = [];
 
@@ -131,7 +131,7 @@ public function hasRuntimeEvaluationsDefinition(): bool
     /**
      * Returns runtime evaluations for the pointcut.
      *
-     * @return array Runtime evaluations
+     * @return array<mixed> Runtime evaluations
      */
     public function getRuntimeEvaluationsDefinition(): array
     {
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Method/MethodTargetExpressionParser.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Method/MethodTargetExpressionParser.php
index dec1266201..b079bc44fc 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Method/MethodTargetExpressionParser.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Method/MethodTargetExpressionParser.php
@@ -30,7 +30,7 @@ class MethodTargetExpressionParser extends PointcutExpressionParser
      * @param string $operator The operator
      * @param string $pointcutExpression The pointcut expression (value of the designator)
      * @param PointcutFilterComposite $pointcutFilterComposite An instance of the pointcut filter composite. The result (ie. the pointcut filter) will be added to this composite object.
-     * @param array &$trace
+     * @param array<mixed> &$trace
      * @return void
      * @throws InvalidPointcutExpressionException
      */
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Parameter/PrivilegeParameterInterface.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Parameter/PrivilegeParameterInterface.php
index 9403192c43..9cc8dfba11 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Parameter/PrivilegeParameterInterface.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Parameter/PrivilegeParameterInterface.php
@@ -41,7 +41,7 @@ public function getName();
     public function getValue();
 
     /**
-     * @return array|null
+     * @return array<mixed>|null
      */
     public function getPossibleValues();
 
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/Parameter/StringPrivilegeParameter.php b/Neos.Flow/Classes/Security/Authorization/Privilege/Parameter/StringPrivilegeParameter.php
index a099e429b2..1cc91f91d4 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/Parameter/StringPrivilegeParameter.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/Parameter/StringPrivilegeParameter.php
@@ -19,7 +19,7 @@
 class StringPrivilegeParameter extends AbstractPrivilegeParameter
 {
     /**
-     * @return array|null
+     * @return array<mixed>|null
      */
     public function getPossibleValues()
     {
diff --git a/Neos.Flow/Classes/Security/Authorization/Privilege/PrivilegeTarget.php b/Neos.Flow/Classes/Security/Authorization/Privilege/PrivilegeTarget.php
index d8b925bce1..42da213bc7 100644
--- a/Neos.Flow/Classes/Security/Authorization/Privilege/PrivilegeTarget.php
+++ b/Neos.Flow/Classes/Security/Authorization/Privilege/PrivilegeTarget.php
@@ -121,7 +121,7 @@ public function hasParameters(): bool
 
     /**
      * @param string $permission one of "GRANT", "DENY" or "ABSTAIN"
-     * @param array $parameters Optional key/value array with parameter names and -values
+     * @param array<string,mixed> $parameters Optional key/value array with parameter names and -values
      * @return PrivilegeInterface
      * @throws SecurityException
      */
@@ -151,7 +151,7 @@ public function getLabel(): string
     }
 
     /**
-     * @param array $parameters
+     * @param array<string,mixed> $parameters
      * @return \Closure
      */
     protected function createParameterMapper(array $parameters): \Closure
@@ -163,7 +163,7 @@ protected function createParameterMapper(array $parameters): \Closure
 
     /**
      * @param PrivilegeParameterDefinition $parameterDefinition
-     * @param array $parameters
+     * @param array<string,mixed> $parameters
      * @return PrivilegeParameterInterface
      * @throws SecurityException
      */
diff --git a/Neos.Flow/Classes/Security/Authorization/PrivilegeManager.php b/Neos.Flow/Classes/Security/Authorization/PrivilegeManager.php
index 6efd9bb355..1eb0a8a031 100644
--- a/Neos.Flow/Classes/Security/Authorization/PrivilegeManager.php
+++ b/Neos.Flow/Classes/Security/Authorization/PrivilegeManager.php
@@ -13,6 +13,7 @@
 
 use Neos\Flow\Annotations as Flow;
 use Neos\Flow\ObjectManagement\ObjectManagerInterface;
+use Neos\Flow\Security\Authorization\Privilege\Parameter\PrivilegeParameterInterface;
 use Neos\Flow\Security\Authorization\Privilege\PrivilegeInterface;
 use Neos\Flow\Security\Context;
 use Neos\Flow\Security\Policy\Role;
@@ -111,7 +112,7 @@ public function isGrantedForRoles(array $roles, $privilegeType, $subject, &$reas
      * Returns true if access is granted on the given privilege target in the current security context
      *
      * @param string $privilegeTargetIdentifier The identifier of the privilege target to decide on
-     * @param array $privilegeParameters Optional array of privilege parameters (simple key => value array)
+     * @param array<PrivilegeParameterInterface> $privilegeParameters Optional array of privilege parameters (simple key => value array)
      * @return boolean true if access is granted, false otherwise
      */
     public function isPrivilegeTargetGranted($privilegeTargetIdentifier, array $privilegeParameters = [])
@@ -124,7 +125,7 @@ public function isPrivilegeTargetGranted($privilegeTargetIdentifier, array $priv
      *
      * @param array<Role> $roles The roles that should be evaluated
      * @param string $privilegeTargetIdentifier The identifier of the privilege target to decide on
-     * @param array $privilegeParameters Optional array of privilege parameters (simple key => value array)
+     * @param array<PrivilegeParameterInterface> $privilegeParameters Optional array of privilege parameters (simple key => value array)
      * @return boolean true if access is granted, false otherwise
      */
     public function isPrivilegeTargetGrantedForRoles(array $roles, $privilegeTargetIdentifier, array $privilegeParameters = [])
@@ -134,7 +135,6 @@ public function isPrivilegeTargetGrantedForRoles(array $roles, $privilegeTargetI
         };
 
         $privileges = array_map($privilegeMapper, $roles);
-        /** @var PrivilegePermissionResult $result */
         $result = array_reduce($privileges, [$this, 'applyPrivilegeToResult'], new PrivilegePermissionResult());
 
         if ($result->getDenies() === 0 && $result->getGrants() > 0) {
diff --git a/Neos.Flow/Classes/Security/Authorization/PrivilegeManagerInterface.php b/Neos.Flow/Classes/Security/Authorization/PrivilegeManagerInterface.php
index da5b738c16..2f2ef9dde4 100644
--- a/Neos.Flow/Classes/Security/Authorization/PrivilegeManagerInterface.php
+++ b/Neos.Flow/Classes/Security/Authorization/PrivilegeManagerInterface.php
@@ -44,7 +44,7 @@ public function isGrantedForRoles(array $roles, $privilegeType, $subject, &$reas
      * Returns true if access is granted on the given privilege target in the current security context
      *
      * @param string $privilegeTargetIdentifier The identifier of the privilege target to decide on
-     * @param array $privilegeParameters Optional array of privilege parameters (simple key => value array)
+     * @param array<mixed> $privilegeParameters Optional array of privilege parameters (simple key => value array)
      * @return boolean true if access is granted, false otherwise
      */
     public function isPrivilegeTargetGranted($privilegeTargetIdentifier, array $privilegeParameters = []);
@@ -54,7 +54,7 @@ public function isPrivilegeTargetGranted($privilegeTargetIdentifier, array $priv
      *
      * @param array<Role> $roles The roles that should be evaluated
      * @param string $privilegeTargetIdentifier The identifier of the privilege target to decide on
-     * @param array $privilegeParameters Optional array of privilege parameters (simple key => value array)
+     * @param array<mixed> $privilegeParameters Optional array of privilege parameters (simple key => value array)
      * @return boolean true if access is granted, false otherwise
      */
     public function isPrivilegeTargetGrantedForRoles(array $roles, $privilegeTargetIdentifier, array $privilegeParameters = []);
diff --git a/Neos.Flow/Classes/Security/Authorization/PrivilegePermissionResult.php b/Neos.Flow/Classes/Security/Authorization/PrivilegePermissionResult.php
index 92eabf6397..5cb35aea57 100644
--- a/Neos.Flow/Classes/Security/Authorization/PrivilegePermissionResult.php
+++ b/Neos.Flow/Classes/Security/Authorization/PrivilegePermissionResult.php
@@ -25,7 +25,7 @@ class PrivilegePermissionResult
     protected $abstains = 0;
 
     /**
-     * @var array
+     * @var array<int,string>
      */
     protected $effectivePrivilegeIdentifiersWithPermission = [];
 
@@ -101,7 +101,7 @@ public function getAbstains(): int
     }
 
     /**
-     * @return array
+     * @return array<int,string>
      */
     public function getEffectivePrivilegeIdentifiersWithPermission(): array
     {
diff --git a/Neos.Flow/Classes/Security/Authorization/TestingPrivilegeManager.php b/Neos.Flow/Classes/Security/Authorization/TestingPrivilegeManager.php
index ef758473b7..696b1c6bb3 100644
--- a/Neos.Flow/Classes/Security/Authorization/TestingPrivilegeManager.php
+++ b/Neos.Flow/Classes/Security/Authorization/TestingPrivilegeManager.php
@@ -51,7 +51,7 @@ public function isGranted($privilegeType, $subject, &$reason = '')
      * or if set based on the override decision value.
      *
      * @param string $privilegeTargetIdentifier The identifier of the privilege target to decide on
-     * @param array $privilegeParameters Optional array of privilege parameters (simple key => value array)
+     * @param array<mixed> $privilegeParameters Optional array of privilege parameters (simple key => value array)
      * @return boolean true if access is granted, false otherwise
      */
     public function isPrivilegeTargetGranted($privilegeTargetIdentifier, array $privilegeParameters = [])
diff --git a/Neos.Flow/Classes/Security/Context.php b/Neos.Flow/Classes/Security/Context.php
index 8726a4265e..f136872125 100644
--- a/Neos.Flow/Classes/Security/Context.php
+++ b/Neos.Flow/Classes/Security/Context.php
@@ -95,7 +95,7 @@ class Context
     protected $csrfProtectionStrategy = self::CSRF_ONE_PER_SESSION;
 
     /**
-     * @var array
+     * @var array<int,string>
      */
     protected $tokenStatusLabels = [
         1 => 'no credentials given',
@@ -149,7 +149,7 @@ class Context
 
     /**
      * CSRF tokens that are valid during this request but will be gone after.
-     * @var array
+     * @var array<string,bool>
      */
     protected $csrfTokensRemovedAfterCurrentRequest = [];
 
@@ -193,7 +193,7 @@ class Context
      * Array of registered global objects that can be accessed as operands
      *
      * @Flow\InjectConfiguration("aop.globalObjects")
-     * @var array
+     * @var array<string,string>
      */
     protected $globalObjects = [];
 
@@ -253,7 +253,7 @@ public function setRequest(ActionRequest $request)
     /**
      * Injects the configuration settings
      *
-     * @param array $settings
+     * @param array<string,mixed> $settings
      * @return void
      * @throws Exception
      */
@@ -624,7 +624,7 @@ public function clearContext()
 
     /**
      * @param Account $account
-     * @return array
+     * @return array<string,Role>
      */
     protected function collectRolesAndParentRolesFromAccount(Account $account): array
     {
@@ -640,7 +640,7 @@ protected function collectRolesAndParentRolesFromAccount(Account $account): arra
 
     /**
      * @param Role $role
-     * @return array
+     * @return array<string,Role>
      */
     protected function collectParentRoles(Role $role): array
     {
@@ -692,6 +692,9 @@ protected function isTokenActive(TokenInterface $token)
             if (isset($requestPatternsByType[$patternType]) && $requestPatternsByType[$patternType] === true) {
                 continue;
             }
+            if (!$this->request) {
+                throw new \Exception('Cannot evaluate request pattern without a request', 1743927165);
+            }
             $requestPatternsByType[$patternType] = $requestPattern->matchRequest($this->request);
         }
         return !in_array(false, $requestPatternsByType, true);
@@ -704,7 +707,7 @@ protected function isTokenActive(TokenInterface $token)
      *
      * @param array<TokenInterface> $managerTokens Array of tokens provided by the authentication manager
      * @param array<TokenInterface> $sessionTokens Array of tokens restored from the session
-     * @return array Array of Authentication\TokenInterface objects
+     * @return array<string,TokenInterface> Array of Authentication\TokenInterface objects
      */
     protected function mergeTokens(array $managerTokens, array $sessionTokens)
     {
@@ -848,6 +851,7 @@ public function getContextHash()
         $this->withoutAuthorizationChecks(function () use (&$contextHashSoFar) {
             foreach ($this->globalObjects as $globalObjectsRegisteredClassName) {
                 if (is_subclass_of($globalObjectsRegisteredClassName, CacheAwareInterface::class)) {
+                    /** @var class-string<CacheAwareInterface> $globalObjectsRegisteredClassName */
                     $globalObject = $this->objectManager->get($globalObjectsRegisteredClassName);
                     $contextHashSoFar .= '<' . $globalObject->getCacheEntryIdentifier();
                 }
diff --git a/Neos.Flow/Classes/Security/Cryptography/Algorithms.php b/Neos.Flow/Classes/Security/Cryptography/Algorithms.php
index f0d1f0c969..20e2e90898 100644
--- a/Neos.Flow/Classes/Security/Cryptography/Algorithms.php
+++ b/Neos.Flow/Classes/Security/Cryptography/Algorithms.php
@@ -32,6 +32,15 @@ class Algorithms
      */
     public static function pbkdf2($password, $salt, $iterationCount, $derivedKeyLength, $algorithm = 'sha256')
     {
+        if (!$algorithm) {
+            throw new \Exception('Algorithm must not be falsy', 1743877215);
+        }
+        if ($iterationCount < 1) {
+            throw new \Exception('Iteration count too low, must be at least 1', 1743877176);
+        }
+        if ($derivedKeyLength < 0) {
+            throw new \Exception('Derived key length too low, must be at least 0', 1743877275);
+        }
         return hash_pbkdf2($algorithm, $password, $salt, $iterationCount, $derivedKeyLength, true);
     }
 }
diff --git a/Neos.Flow/Classes/Security/Cryptography/FileBasedSimpleKeyService.php b/Neos.Flow/Classes/Security/Cryptography/FileBasedSimpleKeyService.php
index a2897353bd..2c9f5876a0 100644
--- a/Neos.Flow/Classes/Security/Cryptography/FileBasedSimpleKeyService.php
+++ b/Neos.Flow/Classes/Security/Cryptography/FileBasedSimpleKeyService.php
@@ -45,7 +45,7 @@ class FileBasedSimpleKeyService
     protected $hashService;
 
     /**
-     * @param array $settings
+     * @param array<string,mixed> $settings
      * @return void
      */
     public function injectSettings(array $settings)
@@ -116,7 +116,7 @@ public function keyExists($name)
      * Returns a key by its name
      *
      * @param string $name
-     * @return boolean
+     * @return string
      * @throws SecurityException
      */
     public function getKey($name)
diff --git a/Neos.Flow/Classes/Security/Cryptography/HashService.php b/Neos.Flow/Classes/Security/Cryptography/HashService.php
index 24df1e3af7..59f567d405 100644
--- a/Neos.Flow/Classes/Security/Cryptography/HashService.php
+++ b/Neos.Flow/Classes/Security/Cryptography/HashService.php
@@ -28,17 +28,17 @@ class HashService
 {
     /**
      * A private, unique key used for encryption tasks
-     * @var string
+     * @var string|false|null
      */
     protected $encryptionKey = null;
 
     /**
-     * @var array
+     * @var array<string,PasswordHashingStrategyInterface>
      */
     protected $passwordHashingStrategies = [];
 
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $strategySettings;
 
@@ -57,7 +57,7 @@ class HashService
     /**
      * Injects the settings of the package this controller belongs to.
      *
-     * @param array $settings Settings container of the current package
+     * @param array<string,mixed> $settings Settings container of the current package
      * @return void
      */
     public function injectSettings(array $settings)
@@ -72,12 +72,8 @@ public function injectSettings(array $settings)
      * @return string The hash of the string
      * @throws InvalidArgumentForHashGenerationException if something else than a string was given as parameter
      */
-    public function generateHmac($string)
+    public function generateHmac(string $string): string
     {
-        if (!is_string($string)) {
-            throw new InvalidArgumentForHashGenerationException('A hash can only be generated for a string, but "' . gettype($string) . '" was given.', 1255069587);
-        }
-
         return hash_hmac('sha1', $string, $this->getEncryptionKey());
     }
 
@@ -121,11 +117,8 @@ public function validateHmac($string, $hmac)
      * @throws InvalidHashException if the hash did not fit to the data.
      * @todo Mark as API once it is more stable
      */
-    public function validateAndStripHmac($string)
+    public function validateAndStripHmac(string $string): string
     {
-        if (!is_string($string)) {
-            throw new InvalidArgumentForHashGenerationException('A hash can only be validated for a string, but "' . gettype($string) . '" was given.', 1320829762);
-        }
         if (strlen($string) < 40) {
             throw new InvalidArgumentForHashGenerationException('A hashed string must contain at least 40 characters, the given string was only ' . strlen($string) . ' characters long.', 1320830276);
         }
@@ -188,12 +181,19 @@ protected function getPasswordHashingStrategyAndIdentifier($strategyIdentifier =
             }
             $strategyIdentifier = $this->strategySettings['default'];
         }
+        if (!is_string($strategyIdentifier)) {
+            throw new \Exception('Invalid strategy identifier', 1743877483);
+        }
 
         if (!isset($this->strategySettings[$strategyIdentifier])) {
             throw new MissingConfigurationException('No hashing strategy with identifier "' . $strategyIdentifier . '" configured', 1320758776);
         }
         $strategyObjectName = $this->strategySettings[$strategyIdentifier];
-        $this->passwordHashingStrategies[$strategyIdentifier] = $this->objectManager->get($strategyObjectName);
+        $strategy = $this->objectManager->get($strategyObjectName);
+        if (!$strategy instanceof PasswordHashingStrategyInterface) {
+            throw new \Exception('Invalid password hashing strategy', 1743877416);
+        }
+        $this->passwordHashingStrategies[$strategyIdentifier] = $strategy;
         return [$this->passwordHashingStrategies[$strategyIdentifier], $strategyIdentifier];
     }
 
diff --git a/Neos.Flow/Classes/Security/Cryptography/Pbkdf2HashingStrategy.php b/Neos.Flow/Classes/Security/Cryptography/Pbkdf2HashingStrategy.php
index e75a985c66..940f61c21c 100644
--- a/Neos.Flow/Classes/Security/Cryptography/Pbkdf2HashingStrategy.php
+++ b/Neos.Flow/Classes/Security/Cryptography/Pbkdf2HashingStrategy.php
@@ -68,6 +68,15 @@ public function __construct(int $dynamicSaltLength, int $iterationCount, int $de
     public function hashPassword($password, $staticSalt = null)
     {
         $dynamicSalt = UtilityAlgorithms::generateRandomBytes($this->dynamicSaltLength);
+        if (!$this->algorithm) {
+            throw new \Exception('Algorithm must not be falsy', 1743877215);
+        }
+        if ($this->iterationCount < 1) {
+            throw new \Exception('Iteration count too low, must be at least 1', 1743877176);
+        }
+        if ($this->derivedKeyLength < 0) {
+            throw new \Exception('Derived key length too low, must be at least 0', 1743877275);
+        }
         $result = hash_pbkdf2($this->algorithm, $password, $dynamicSalt . $staticSalt, $this->iterationCount, $this->derivedKeyLength, true);
         return base64_encode($dynamicSalt) . ',' . base64_encode($result);
     }
@@ -88,6 +97,12 @@ public function validatePassword($password, $hashedPasswordAndSalt, $staticSalt
         if (count($parts) !== 2) {
             throw new \InvalidArgumentException('The derived key with salt must contain a salt, separated with a comma from the derived key', 1306172911);
         }
+        if (!$this->algorithm) {
+            throw new \Exception('Algorithm must not be falsy', 1743877215);
+        }
+        if ($this->iterationCount < 1) {
+            throw new \Exception('Iteration count too low, must be at least 1', 1743877176);
+        }
         $dynamicSalt = base64_decode($parts[0]);
         $derivedKey = base64_decode($parts[1]);
         $derivedKeyLength = strlen($derivedKey);
diff --git a/Neos.Flow/Classes/Security/Cryptography/RsaWalletServiceInterface.php b/Neos.Flow/Classes/Security/Cryptography/RsaWalletServiceInterface.php
index 8803d39061..c839393a1e 100644
--- a/Neos.Flow/Classes/Security/Cryptography/RsaWalletServiceInterface.php
+++ b/Neos.Flow/Classes/Security/Cryptography/RsaWalletServiceInterface.php
@@ -54,7 +54,7 @@ public function registerPublicKeyFromString($publicKeyString);
      * @return OpenSslRsaKey The public key
      * @throws InvalidKeyPairIdException If the given fingerprint identifies no valid key pair
      */
-    public function getPublicKey($fingerprint);
+    public function getPublicKey(string $fingerprint): OpenSslRsaKey;
 
     /**
      * Decrypts the given cypher with the private key identified by the given fingerprint
@@ -67,7 +67,7 @@ public function getPublicKey($fingerprint);
      * @throws InvalidKeyPairIdException If the given fingerprint identifies no valid keypair
      * @throws DecryptionNotAllowedException If the given fingerprint identifies a keypair for encrypted passwords
      */
-    public function decrypt($cypher, $fingerprint);
+    public function decrypt(string $cypher, string $fingerprint): string;
 
     /**
      * Signs the given plaintext with the private key identified by the given fingerprint
@@ -77,7 +77,7 @@ public function decrypt($cypher, $fingerprint);
      * @return string The signature of the given plaintext
      * @throws InvalidKeyPairIdException If the given fingerprint identifies no valid keypair
      */
-    public function sign($plaintext, $fingerprint);
+    public function sign(string $plaintext, string $fingerprint): string;
 
     /**
      * Checks whether the given signature is valid for the given plaintext
@@ -88,7 +88,7 @@ public function sign($plaintext, $fingerprint);
      * @param string $fingerprint The fingerprint to identify to correct public key
      * @return boolean true if the signature is correct for the given plaintext and public key
      */
-    public function verifySignature($plaintext, $signature, $fingerprint);
+    public function verifySignature(string $plaintext, string $signature, string $fingerprint): bool;
 
     /**
      * Encrypts the given plaintext with the public key identified by the given fingerprint
@@ -109,14 +109,12 @@ public function encryptWithPublicKey($plaintext, $fingerprint);
      * @param string $fingerprint The fingerprint to identify to correct private key
      * @return boolean true if the password is correct
      */
-    public function checkRSAEncryptedPassword($encryptedPassword, $passwordHash, $salt, $fingerprint);
+    public function checkRSAEncryptedPassword(string $encryptedPassword, string $passwordHash, string $salt, string $fingerprint): bool;
 
     /**
      * Destroys the keypair identified by the given fingerprint
      *
-     * @param string $fingerprint The fingerprint
-     * @return void
      * @throws InvalidKeyPairIdException If the given fingerprint identifies no valid key pair
      */
-    public function destroyKeypair($fingerprint);
+    public function destroyKeypair(string $fingerprint): void;
 }
diff --git a/Neos.Flow/Classes/Security/Cryptography/RsaWalletServicePhp.php b/Neos.Flow/Classes/Security/Cryptography/RsaWalletServicePhp.php
index e861eb01ea..e302021639 100644
--- a/Neos.Flow/Classes/Security/Cryptography/RsaWalletServicePhp.php
+++ b/Neos.Flow/Classes/Security/Cryptography/RsaWalletServicePhp.php
@@ -31,13 +31,13 @@ class RsaWalletServicePhp implements RsaWalletServiceInterface
     protected $keystorePathAndFilename;
 
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $keys = [];
 
     /**
      * The openSSL configuration
-     * @var array
+     * @var array<mixed>
      */
     protected $openSSLConfiguration = [];
 
@@ -55,7 +55,7 @@ class RsaWalletServicePhp implements RsaWalletServiceInterface
     /**
      * Injects the OpenSSL configuration to be used
      *
-     * @param array $settings
+     * @param array<string,mixed> $settings
      * @return void
      * @throws MissingConfigurationException
      * @throws SecurityException
@@ -88,7 +88,7 @@ public function injectSettings(array $settings)
     public function initializeObject()
     {
         if (file_exists($this->keystorePathAndFilename)) {
-            $this->keys = unserialize(file_get_contents($this->keystorePathAndFilename), ['allowed_classes' => [OpenSslRsaKey::class]]);
+            $this->keys = unserialize(file_get_contents($this->keystorePathAndFilename) ?: '', ['allowed_classes' => [OpenSslRsaKey::class]]);
         }
         $this->saveKeysOnShutdown = false;
     }
@@ -128,6 +128,9 @@ public function generateNewKeypair($usedForPasswords = false)
     public function registerKeyPairFromPrivateKeyString($privateKeyString, $usedForPasswords = false)
     {
         $keyResource = openssl_pkey_get_private($privateKeyString);
+        if ($keyResource === false) {
+            throw new \Exception('Failed to load private key', 1743877014);
+        }
 
         $modulus = $this->getModulus($keyResource);
         $publicKeyString = $this->getPublicKeyString($keyResource);
@@ -149,6 +152,9 @@ public function registerKeyPairFromPrivateKeyString($privateKeyString, $usedForP
     public function registerPublicKeyFromString($publicKeyString)
     {
         $keyResource = openssl_pkey_get_public($publicKeyString);
+        if ($keyResource === false) {
+            throw new \Exception('Failed to load public key', 1743876948);
+        }
 
         $modulus = $this->getModulus($keyResource);
         $publicKey = new OpenSslRsaKey($modulus, $publicKeyString);
@@ -163,9 +169,9 @@ public function registerPublicKeyFromString($publicKeyString)
      * @return OpenSslRsaKey The public key
      * @throws InvalidKeyPairIdException If the given fingerprint identifies no valid key pair
      */
-    public function getPublicKey($fingerprint)
+    public function getPublicKey(string $fingerprint): OpenSslRsaKey
     {
-        if ($fingerprint === null || !isset($this->keys[$fingerprint])) {
+        if (!isset($this->keys[$fingerprint])) {
             throw new InvalidKeyPairIdException('Invalid keypair fingerprint given', 1231438860);
         }
 
@@ -199,16 +205,16 @@ public function encryptWithPublicKey($plaintext, $fingerprint)
      * Note: You should never decrypt a password with this function. Use checkRSAEncryptedPassword()
      * to check passwords!
      *
-     * @param string $cipher cipher text to decrypt
+     * @param string $cypher cipher text to decrypt
      * @param string $fingerprint The fingerprint to identify the private key (RSA public key fingerprint)
      * @return string The decrypted text
      * @throws InvalidKeyPairIdException If the given fingerprint identifies no valid keypair
      * @throws DecryptionNotAllowedException If the given fingerprint identifies a keypair for encrypted passwords
      * @throws SecurityException If decryption failed for some other reason
      */
-    public function decrypt($cipher, $fingerprint)
+    public function decrypt(string $cypher, string $fingerprint): string
     {
-        if ($fingerprint === null || !isset($this->keys[$fingerprint])) {
+        if (!isset($this->keys[$fingerprint])) {
             throw new InvalidKeyPairIdException('Invalid keypair fingerprint given', 1231438861);
         }
 
@@ -218,7 +224,7 @@ public function decrypt($cipher, $fingerprint)
             throw new DecryptionNotAllowedException('You are not allowed to decrypt passwords!', 1233655350);
         }
 
-        return $this->decryptWithPrivateKey($cipher, $keyPair['privateKey']);
+        return $this->decryptWithPrivateKey($cypher, $keyPair['privateKey']);
     }
 
     /**
@@ -229,9 +235,9 @@ public function decrypt($cipher, $fingerprint)
      * @return string The signature of the given plaintext
      * @throws InvalidKeyPairIdException If the given fingerprint identifies no valid keypair
      */
-    public function sign($plaintext, $fingerprint)
+    public function sign(string $plaintext, string $fingerprint): string
     {
-        if ($fingerprint === null || !isset($this->keys[$fingerprint])) {
+        if (!isset($this->keys[$fingerprint])) {
             throw new InvalidKeyPairIdException('Invalid keypair fingerprint given', 1299095799);
         }
 
@@ -251,9 +257,9 @@ public function sign($plaintext, $fingerprint)
      * @return boolean true if the signature is correct for the given plaintext and public key
      * @throws InvalidKeyPairIdException
      */
-    public function verifySignature($plaintext, $signature, $fingerprint)
+    public function verifySignature(string $plaintext, string $signature, string $fingerprint): bool
     {
-        if ($fingerprint === null || !isset($this->keys[$fingerprint])) {
+        if (!isset($this->keys[$fingerprint])) {
             throw new InvalidKeyPairIdException('Invalid keypair fingerprint given', 1304959763);
         }
 
@@ -273,9 +279,9 @@ public function verifySignature($plaintext, $signature, $fingerprint)
      * @return boolean true if the password is correct
      * @throws InvalidKeyPairIdException If the given fingerprint identifies no valid keypair
      */
-    public function checkRSAEncryptedPassword($encryptedPassword, $passwordHash, $salt, $fingerprint)
+    public function checkRSAEncryptedPassword(string $encryptedPassword, string $passwordHash, string $salt, string $fingerprint): bool
     {
-        if ($fingerprint === null || !isset($this->keys[$fingerprint])) {
+        if (!isset($this->keys[$fingerprint])) {
             throw new InvalidKeyPairIdException('Invalid keypair fingerprint given', 1233655216);
         }
 
@@ -288,12 +294,11 @@ public function checkRSAEncryptedPassword($encryptedPassword, $passwordHash, $sa
      * Destroys the keypair identified by the given fingerprint
      *
      * @param string $fingerprint The fingerprint
-     * @return void
      * @throws InvalidKeyPairIdException If the given fingerprint identifies no valid key pair
      */
-    public function destroyKeypair($fingerprint)
+    public function destroyKeypair(string $fingerprint): void
     {
-        if ($fingerprint === null || !isset($this->keys[$fingerprint])) {
+        if (!isset($this->keys[$fingerprint])) {
             throw new InvalidKeyPairIdException('Invalid keypair fingerprint given', 1231438863);
         }
 
@@ -322,6 +327,9 @@ private function getPrivateKeyString(\OpenSSLAsymmetricKey $keyResource)
     private function getPublicKeyString(\OpenSSLAsymmetricKey $keyResource)
     {
         $keyDetails = openssl_pkey_get_details($keyResource);
+        if ($keyDetails === false) {
+            throw new \Exception('Failed to get public key details', 1743876036);
+        }
 
         return $keyDetails['key'];
     }
@@ -335,6 +343,9 @@ private function getPublicKeyString(\OpenSSLAsymmetricKey $keyResource)
     private function getModulus(\OpenSSLAsymmetricKey $keyResource)
     {
         $keyDetails = openssl_pkey_get_details($keyResource);
+        if ($keyDetails === false) {
+            throw new \Exception('Failed to load public key details', 1743875916);
+        }
         return strtoupper(bin2hex($keyDetails['rsa']['n']));
     }
 
@@ -350,6 +361,9 @@ private function decryptWithPrivateKey($cipher, OpenSslRsaKey $privateKey)
     {
         $decrypted = '';
         $key = openssl_pkey_get_private($privateKey->getKeyString());
+        if ($key === false) {
+            throw new \Exception('Failed to load private key', 1743875855);
+        }
         if (openssl_private_decrypt($cipher, $decrypted, $key, $this->paddingAlgorithm) === false) {
             // Fallback for data that was encrypted with old default OPENSSL_PKCS1_PADDING
             if ($this->paddingAlgorithm !== OPENSSL_PKCS1_PADDING) {
@@ -374,7 +388,7 @@ private function decryptWithPrivateKey($cipher, OpenSslRsaKey $privateKey)
      * consistent key access.
      *
      * @param OpenSslRsaKey $publicKey The public key
-     * @param OpenSslRsaKey $privateKey The private key
+     * @param OpenSslRsaKey|null $privateKey The private key
      * @param boolean $usedForPasswords true if this keypair should be used to encrypt passwords (then decryption won't be allowed!).
      * @return string The fingerprint which is used as an identifier for storing the key pair
      */
@@ -439,7 +453,13 @@ public function shutdownObject()
     public function getFingerprintByPublicKey($publicKeyString)
     {
         $keyResource = openssl_pkey_get_public($publicKeyString);
+        if ($keyResource === false) {
+            throw new \Exception('Could not extract public key', 1743875618);
+        }
         $keyDetails = openssl_pkey_get_details($keyResource);
+        if ($keyDetails === false) {
+            throw new \Exception('Could not extract public key details', 1743875650);
+        }
         $modulus = $this->sshConvertMpint($keyDetails['rsa']['n']);
         $publicExponent = $this->sshConvertMpint($keyDetails['rsa']['e']);
 
diff --git a/Neos.Flow/Classes/Security/DummyContext.php b/Neos.Flow/Classes/Security/DummyContext.php
index a9689677ef..57474421d9 100644
--- a/Neos.Flow/Classes/Security/DummyContext.php
+++ b/Neos.Flow/Classes/Security/DummyContext.php
@@ -35,7 +35,7 @@ class DummyContext extends Context
 
     /**
      * Array of configured tokens (might have request patterns)
-     * @var array
+     * @var array<TokenInterface>
      */
     protected $tokens = [];
 
@@ -86,7 +86,7 @@ public function getAuthenticationStrategy()
      * Sets the Authentication\Tokens of the security context which should be active.
      *
      * @param TokenInterface[] $tokens Array of set tokens
-     * @return array
+     * @return array<TokenInterface>
      */
     public function setAuthenticationTokens(array $tokens)
     {
@@ -110,7 +110,7 @@ public function getAuthenticationTokens()
      * active for the current request and of the given type. If a token has a request pattern that cannot match
      * against the current request it is determined as not active.
      *
-     * @param string $className The class name
+     * @param class-string<TokenInterface> $className The class name
      * @return TokenInterface[] Array of set tokens of the specified type
      */
     public function getAuthenticationTokensOfType($className)
@@ -132,7 +132,7 @@ public function getAuthenticationTokensOfType($className)
      *
      * The "Neos.Flow:Everybody" roles is always returned.
      *
-     * @return Role[]
+     * @return Role[]|null
      */
     public function getRoles()
     {
@@ -185,7 +185,7 @@ public function setCsrfProtectionToken($csrfProtectionToken)
      * Returns the current CSRF protection token. A new one is created when needed, depending on the  configured CSRF
      * protection strategy.
      *
-     * @return string
+     * @return string|null
      */
     public function getCsrfProtectionToken()
     {
@@ -231,7 +231,7 @@ public function setInterceptedRequest(?ActionRequest $interceptedRequest = null)
      * Returns the request, that has been stored for later resuming after it
      * has been intercepted by a security exception, NULL if there is none.
      *
-     * @return ActionRequest
+     * @return ActionRequest|null
      */
     public function getInterceptedRequest()
     {
diff --git a/Neos.Flow/Classes/Security/Policy/PolicyService.php b/Neos.Flow/Classes/Security/Policy/PolicyService.php
index f2e8228ccb..aab68aa904 100644
--- a/Neos.Flow/Classes/Security/Policy/PolicyService.php
+++ b/Neos.Flow/Classes/Security/Policy/PolicyService.php
@@ -46,7 +46,7 @@ class PolicyService
     protected $configurationManager;
 
     /**
-     * @var array
+     * @var array<mixed>
      */
     protected $policyConfiguration;
 
@@ -198,7 +198,7 @@ protected function initializePrivilegeTargets(): void
                     if ($parameterClassName === null) {
                         throw new SecurityException(sprintf('No "className" defined for parameter "%s" in privilegeTarget "%s"', $parameterName, $privilegeTargetIdentifier), 1396021782);
                     }
-                    if (!in_array(PrivilegeParameterInterface::class, class_implements($parameterClassName), true)) {
+                    if (!in_array(PrivilegeParameterInterface::class, class_implements($parameterClassName) ?: [], true)) {
                         throw new SecurityException(sprintf('PrivilegeParameterInterface must be implemented for "className" defined for parameter "%s" in privilegeTarget "%s"', $parameterName, $privilegeTargetIdentifier), 1396021782);
                     }
                     $parameterDefinitions[$parameterName] = new PrivilegeParameterDefinition($parameterName, $parameterClassName);
@@ -266,7 +266,7 @@ public function getRoles($includeAbstract = false): array
      * Returns all privileges of the given type
      *
      * @param string $type Full qualified class or interface name
-     * @return array
+     * @return array<PrivilegeInterface>
      * @throws InvalidConfigurationTypeException
      * @throws SecurityException
      */
@@ -325,7 +325,7 @@ public function reset(): void
      * This signal can be used to add roles and/or privilegeTargets during runtime. In the slot make sure to receive the
      * $policyConfiguration array by reference so you can alter it.
      *
-     * @param array $policyConfiguration The policy configuration
+     * @param array<mixed> $policyConfiguration The policy configuration
      * @return void
      * @Flow\Signal
      */
diff --git a/Neos.Flow/Classes/Security/Policy/Role.php b/Neos.Flow/Classes/Security/Policy/Role.php
index e4ae2790ac..b1e5968140 100644
--- a/Neos.Flow/Classes/Security/Policy/Role.php
+++ b/Neos.Flow/Classes/Security/Policy/Role.php
@@ -14,6 +14,7 @@
  */
 
 use Neos\Flow\Annotations as Flow;
+use Neos\Flow\Security\Authorization\Privilege\Parameter\PrivilegeParameterInterface;
 use Neos\Flow\Security\Authorization\Privilege\PrivilegeInterface;
 
 /**
@@ -246,7 +247,7 @@ public function getPrivilegesByType(string $className): array
 
     /**
      * @param string $privilegeTargetIdentifier
-     * @param array $privilegeParameters
+     * @param array<PrivilegeParameterInterface> $privilegeParameters
      * @return PrivilegeInterface|null the matching privilege or NULL if no privilege exists for the given constraints
      */
     public function getPrivilegeForTarget(string $privilegeTargetIdentifier, array $privilegeParameters = []): ?PrivilegeInterface
diff --git a/Neos.Flow/Classes/Security/Policy/RoleConverter.php b/Neos.Flow/Classes/Security/Policy/RoleConverter.php
index bd599cb85d..b90c842404 100644
--- a/Neos.Flow/Classes/Security/Policy/RoleConverter.php
+++ b/Neos.Flow/Classes/Security/Policy/RoleConverter.php
@@ -52,7 +52,7 @@ class RoleConverter extends AbstractTypeConverter
      *
      * @param mixed $source
      * @param string $targetType
-     * @param array $convertedChildProperties
+     * @param array<mixed> $convertedChildProperties
      * @param PropertyMappingConfigurationInterface|null $configuration
      * @return object the target type
      */
diff --git a/Neos.Flow/Classes/Security/RequestPattern/ControllerObjectName.php b/Neos.Flow/Classes/Security/RequestPattern/ControllerObjectName.php
index b95619530c..9c61769698 100644
--- a/Neos.Flow/Classes/Security/RequestPattern/ControllerObjectName.php
+++ b/Neos.Flow/Classes/Security/RequestPattern/ControllerObjectName.php
@@ -21,14 +21,14 @@
 class ControllerObjectName implements RequestPatternInterface
 {
     /**
-     * @var array
+     * @var array<string,string>
      */
     protected $options;
 
     /**
      * Expects options in the form array('controllerObjectNamePattern' => '<regularExpression>')
      *
-     * @param array $options
+     * @param array<string,string> $options
      */
     public function __construct(array $options)
     {
diff --git a/Neos.Flow/Classes/Security/RequestPattern/CsrfProtection.php b/Neos.Flow/Classes/Security/RequestPattern/CsrfProtection.php
index ffa2eef7e2..f7a7bc8922 100644
--- a/Neos.Flow/Classes/Security/RequestPattern/CsrfProtection.php
+++ b/Neos.Flow/Classes/Security/RequestPattern/CsrfProtection.php
@@ -101,6 +101,9 @@ public function matchRequest(ActionRequest $request)
         }
 
         $controllerClassName = $this->objectManager->getClassNameByObjectName($request->getControllerObjectName());
+        if ($controllerClassName === false) {
+            throw new \Exception('Failed to resolve controller class name for ' . $request->getControllerObjectName(), 1743926779);
+        }
         $actionMethodName = $request->getControllerActionName() . 'Action';
 
         if (!$this->hasPolicyEntryForMethod($controllerClassName, $actionMethodName)) {
diff --git a/Neos.Flow/Classes/Security/RequestPattern/Host.php b/Neos.Flow/Classes/Security/RequestPattern/Host.php
index 1b1c1a00a9..3265905e68 100644
--- a/Neos.Flow/Classes/Security/RequestPattern/Host.php
+++ b/Neos.Flow/Classes/Security/RequestPattern/Host.php
@@ -25,14 +25,14 @@
 class Host implements RequestPatternInterface
 {
     /**
-     * @var array
+     * @var array<string,string>
      */
     protected $options;
 
     /**
      * Expects options in the form array('hostPattern' => '<host pattern>')
      *
-     * @param array $options
+     * @param array<string,string> $options
      */
     public function __construct(array $options)
     {
diff --git a/Neos.Flow/Classes/Security/RequestPattern/Ip.php b/Neos.Flow/Classes/Security/RequestPattern/Ip.php
index 18cf903ad5..02358ebf46 100644
--- a/Neos.Flow/Classes/Security/RequestPattern/Ip.php
+++ b/Neos.Flow/Classes/Security/RequestPattern/Ip.php
@@ -35,14 +35,14 @@
 class Ip implements RequestPatternInterface
 {
     /**
-     * @var array
+     * @var array<string,string>
      */
     protected $options;
 
     /**
      * Expects options in the form array('cidrPattern' => '<CIDR IP Pattern>')
      *
-     * @param array $options
+     * @param array<string,string> $options
      */
     public function __construct(array $options)
     {
diff --git a/Neos.Flow/Classes/Security/RequestPattern/Uri.php b/Neos.Flow/Classes/Security/RequestPattern/Uri.php
index 9127691d1b..0121585cf1 100644
--- a/Neos.Flow/Classes/Security/RequestPattern/Uri.php
+++ b/Neos.Flow/Classes/Security/RequestPattern/Uri.php
@@ -21,14 +21,14 @@
 class Uri implements RequestPatternInterface
 {
     /**
-     * @var array
+     * @var array<string,string>
      */
     protected $options;
 
     /**
      * Expects options in the form array('uriPattern' => '<URI pattern>')
      *
-     * @param array $options
+     * @param array<string,string> $options
      */
     public function __construct(array $options)
     {
diff --git a/Neos.Flow/Classes/Security/SessionDataContainer.php b/Neos.Flow/Classes/Security/SessionDataContainer.php
index d35fb8e870..5741c6e519 100644
--- a/Neos.Flow/Classes/Security/SessionDataContainer.php
+++ b/Neos.Flow/Classes/Security/SessionDataContainer.php
@@ -4,6 +4,7 @@
 use Neos\Flow\Annotations as Flow;
 use Neos\Flow\Mvc\ActionRequest;
 use Neos\Flow\Security\Authentication\Token\SessionlessTokenInterface;
+use Neos\Flow\Security\Authentication\TokenInterface;
 
 /**
  * @Flow\Scope("session")
@@ -14,14 +15,14 @@ class SessionDataContainer
     /**
      * The current list of security tokens.
      *
-     * @var array
+     * @var array<TokenInterface>
      */
     protected $securityTokens = [];
 
     /**
      * The current list of CSRF tokens
      *
-     * @var array
+     * @var array<string,string|bool>
      */
     protected $csrfProtectionTokens = [];
 
@@ -35,7 +36,7 @@ class SessionDataContainer
     /**
      * Get the current list of security tokens.
      *
-     * @return array
+     * @return array<TokenInterface>
      */
     public function getSecurityTokens(): array
     {
@@ -45,9 +46,9 @@ public function getSecurityTokens(): array
     /**
      * Set the current list of security tokens with their data.
      *
-     * @param array $securityTokens
+     * @param array<TokenInterface> $securityTokens
      */
-    public function setSecurityTokens(array $securityTokens)
+    public function setSecurityTokens(array $securityTokens): void
     {
         foreach ($securityTokens as $token) {
             if ($token instanceof SessionlessTokenInterface) {
@@ -60,7 +61,7 @@ public function setSecurityTokens(array $securityTokens)
     /**
      * Get the current list of active CSRF tokens.
      *
-     * @return array
+     * @return array<string,string|bool>
      */
     public function getCsrfProtectionTokens(): array
     {
@@ -70,9 +71,9 @@ public function getCsrfProtectionTokens(): array
     /**
      * set the list of currently active CSRF tokens.
      *
-     * @param array $csrfProtectionTokens
+     * @param array<string,string|bool> $csrfProtectionTokens
      */
-    public function setCsrfProtectionTokens(array $csrfProtectionTokens)
+    public function setCsrfProtectionTokens(array $csrfProtectionTokens): void
     {
         $this->csrfProtectionTokens = $csrfProtectionTokens;
     }
diff --git a/Neos.Flow/Classes/Session/Aspect/LazyLoadingAspect.php b/Neos.Flow/Classes/Session/Aspect/LazyLoadingAspect.php
index 6254dd84a7..996819e604 100644
--- a/Neos.Flow/Classes/Session/Aspect/LazyLoadingAspect.php
+++ b/Neos.Flow/Classes/Session/Aspect/LazyLoadingAspect.php
@@ -29,6 +29,9 @@ class LazyLoadingAspect
     #[Flow\Inject]
     protected ?LoggerInterface $logger = null;
 
+    /**
+     * @var array<string,object>
+     */
     protected array $sessionOriginalInstances = [];
 
     public function __construct(
diff --git a/Neos.Flow/Classes/Session/Aspect/SessionObjectMethodsPointcutFilter.php b/Neos.Flow/Classes/Session/Aspect/SessionObjectMethodsPointcutFilter.php
index 1f89a3be0b..0f4e24cefe 100644
--- a/Neos.Flow/Classes/Session/Aspect/SessionObjectMethodsPointcutFilter.php
+++ b/Neos.Flow/Classes/Session/Aspect/SessionObjectMethodsPointcutFilter.php
@@ -37,7 +37,7 @@ public function injectObjectManager(CompileTimeObjectManager $objectManager): vo
      * Checks if the specified class and method matches against the filter
      *
      * @param string $className Name of the class to check against
-     * @param string $methodName Name of the method to check against
+     * @param ?string $methodName Name of the method to check against
      * @param string $methodDeclaringClassName Name of the class the method was originally declared in
      * @param mixed $pointcutQueryIdentifier Some identifier for this query - must at least differ from a previous identifier. Used for circular reference detection.
      * @return bool true if the class / method match, otherwise false
@@ -79,7 +79,7 @@ public function hasRuntimeEvaluationsDefinition(): bool
     /**
      * Returns runtime evaluations for a previously matched pointcut
      *
-     * @return array Runtime evaluations
+     * @return array<mixed> Runtime evaluations
      */
     public function getRuntimeEvaluationsDefinition(): array
     {
diff --git a/Neos.Flow/Classes/Session/CookieEnabledInterface.php b/Neos.Flow/Classes/Session/CookieEnabledInterface.php
index 522f07079c..c722999dad 100644
--- a/Neos.Flow/Classes/Session/CookieEnabledInterface.php
+++ b/Neos.Flow/Classes/Session/CookieEnabledInterface.php
@@ -18,5 +18,8 @@ interface CookieEnabledInterface extends SessionInterface
 {
     public function getSessionCookie(): Cookie;
 
+    /**
+     * @param array<string> $tags
+     */
     public static function createFromCookieAndSessionInformation(Cookie $sessionCookie, string $storageIdentifier, int $lastActivityTimestamp, array $tags = []): SessionInterface|CookieEnabledInterface;
 }
diff --git a/Neos.Flow/Classes/Session/Data/SessionKeyValueStore.php b/Neos.Flow/Classes/Session/Data/SessionKeyValueStore.php
index 18793fcaf5..a4ec948c1e 100644
--- a/Neos.Flow/Classes/Session/Data/SessionKeyValueStore.php
+++ b/Neos.Flow/Classes/Session/Data/SessionKeyValueStore.php
@@ -72,6 +72,9 @@ public function store(StorageIdentifier $storageIdentifier, string $key, mixed $
     {
         $entryIdentifier = $this->createEntryIdentifier($storageIdentifier, $key);
         $serializedValue = ($this->useIgBinary === true) ? igbinary_serialize($value) : serialize($value);
+        if (is_null($serializedValue)) {
+            throw new \Exception('Failed to serialize value', 1743874462);
+        }
         $valueHash = md5($serializedValue);
         $debounceHash = $this->writeDebounceHashes[$storageIdentifier->value][$key] ?? null;
         if ($debounceHash !== null && $debounceHash === $valueHash) {
@@ -90,7 +93,7 @@ public function remove(StorageIdentifier $storageIdentifier): int
         return $this->cache->flushByTag($storageIdentifier->value);
     }
 
-    private function createEntryIdentifier(StorageIdentifier $storageIdentifier, $key): string
+    private function createEntryIdentifier(StorageIdentifier $storageIdentifier, string $key): string
     {
         return $storageIdentifier->value . md5($key);
     }
diff --git a/Neos.Flow/Classes/Session/Data/SessionMetaDataStore.php b/Neos.Flow/Classes/Session/Data/SessionMetaDataStore.php
index a61eec9bff..81a21f9905 100644
--- a/Neos.Flow/Classes/Session/Data/SessionMetaDataStore.php
+++ b/Neos.Flow/Classes/Session/Data/SessionMetaDataStore.php
@@ -82,6 +82,15 @@ public function retrieve(SessionIdentifier $sessionIdentifier): ?SessionMetaData
         }
 
         if (is_array($metaDataFromCache)) {
+            if (!is_string($metaDataFromCache['storageIdentifier'] ?? null)) {
+                throw new \Exception('Missing storageIdentifier', 1743874214);
+            }
+            if (!is_int($metaDataFromCache['lastActivityTimestamp'])) {
+                throw new \Exception('Missing lastActivityTimestamp', 1743874236);
+            }
+            if (!is_array($metaDataFromCache['tags'])) {
+                throw new \Exception('Missing tags', 1743874272);
+            }
             $metaDataFromCache = SessionMetaData::createFromSessionIdentifierStringAndOldArrayCacheFormat($sessionIdentifier->value, $metaDataFromCache);
             $this->writeDebounceCache[$metaDataFromCache->sessionIdentifier->value] = $metaDataFromCache;
             return $metaDataFromCache;
@@ -104,6 +113,15 @@ public function retrieveByTag(string $tag): \Generator
                 $this->writeDebounceCache[$sessionIdentifier] = $sessionMetaData;
                 yield $sessionIdentifier => $sessionMetaData;
             } elseif (is_array($sessionMetaData)) {
+                if (!is_string($sessionMetaData['storageIdentifier'] ?? null)) {
+                    throw new \Exception('Missing storageIdentifier', 1743874214);
+                }
+                if (!is_int($sessionMetaData['lastActivityTimestamp'])) {
+                    throw new \Exception('Missing lastActivityTimestamp', 1743874236);
+                }
+                if (!is_array($sessionMetaData['tags'])) {
+                    throw new \Exception('Missing tags', 1743874272);
+                }
                 $sessionMetaData = SessionMetaData::createFromSessionIdentifierStringAndOldArrayCacheFormat($sessionIdentifier, $sessionMetaData);
                 $this->writeDebounceCache[$sessionIdentifier] = $sessionMetaData;
                 yield $sessionIdentifier => $sessionMetaData;
@@ -125,7 +143,19 @@ public function retrieveAll(): \Generator
                 $this->writeDebounceCache[$sessionIdentifier] = $sessionMetaData;
                 yield $sessionIdentifier => $sessionMetaData;
             } elseif (is_array($sessionMetaData)) {
-                $sessionMetaData = SessionMetaData::createFromSessionIdentifierStringAndOldArrayCacheFormat($sessionIdentifier, $sessionMetaData);
+                if (!is_string($sessionMetaData['storageIdentifier'] ?? null)) {
+                    throw new \Exception('Missing storageIdentifier', 1743874214);
+                }
+                if (!is_int($sessionMetaData['lastActivityTimestamp'])) {
+                    throw new \Exception('Missing lastActivityTimestamp', 1743874236);
+                }
+                if (!is_array($sessionMetaData['tags'])) {
+                    throw new \Exception('Missing tags', 1743874272);
+                }
+                $sessionMetaData = SessionMetaData::createFromSessionIdentifierStringAndOldArrayCacheFormat(
+                    $sessionIdentifier,
+                    $sessionMetaData
+                );
                 $this->writeDebounceCache[$sessionIdentifier] = $sessionMetaData;
                 yield $sessionIdentifier => $sessionMetaData;
             }
diff --git a/Neos.Flow/Classes/Session/Session.php b/Neos.Flow/Classes/Session/Session.php
index 1d67a029b9..8233bb8d13 100644
--- a/Neos.Flow/Classes/Session/Session.php
+++ b/Neos.Flow/Classes/Session/Session.php
@@ -71,6 +71,9 @@ class Session implements CookieEnabledInterface
     protected ?string $sessionCookieSameSite = null;
     protected ?Cookie $sessionCookie = null;
     protected int $inactivityTimeout;
+    /**
+     * @var array<string>
+     */
     protected array $tags = [];
     protected int $now = 0;
     protected ?SessionMetaData $sessionMetaData = null;
@@ -91,7 +94,10 @@ public static function create(): self
         return new static();
     }
 
-    public static function createRemote(string $sessionIdentifier, string $storageIdentifier, ?int $lastActivityTimestamp = null, array $tags = []): self
+    /**
+     * @param array<string> $tags
+     */
+    public static function createRemote(string $sessionIdentifier, string $storageIdentifier, int $lastActivityTimestamp, array $tags = []): self
     {
         $session = new static();
         $session->sessionMetaData = new SessionMetaData(
@@ -114,6 +120,9 @@ public static function createRemoteFromSessionMetaData(SessionMetaData $sessionM
         return $session;
     }
 
+    /**
+     * @param array<string> $tags
+     */
     public static function createFromCookieAndSessionInformation(Cookie $sessionCookie, string $storageIdentifier, int $lastActivityTimestamp, array $tags = []): SessionInterface|CookieEnabledInterface
     {
         $session = new static();
@@ -127,6 +136,9 @@ public static function createFromCookieAndSessionInformation(Cookie $sessionCook
         return $session;
     }
 
+    /**
+     * @param array<string,mixed> $settings
+     */
     public function injectSettings(array $settings): void
     {
         $this->sessionCookieName = $settings['session']['name'];
@@ -141,6 +153,9 @@ public function injectSettings(array $settings): void
 
     public function getSessionCookie(): Cookie
     {
+        if (!$this->sessionCookie) {
+            throw new \Exception('Missing session cookie');
+        }
         return $this->sessionCookie;
     }
 
@@ -172,6 +187,9 @@ public function start(): void
     {
         if ($this->started === false) {
             $this->sessionMetaData = SessionMetaData::createWithTimestamp($this->now);
+            if (!$this->sessionCookiePath) {
+                throw new \Exception('Cannot start a session without a path');
+            }
             $this->sessionCookie = new Cookie($this->sessionCookieName, $this->sessionMetaData->sessionIdentifier->value, 0, $this->sessionCookieLifetime, $this->sessionCookieDomain, $this->sessionCookiePath, $this->sessionCookieSecure, $this->sessionCookieHttpOnly, $this->sessionCookieSameSite);
             $this->started = true;
 
@@ -221,6 +239,9 @@ public function canBeResumed(): bool
     public function resume(): ?int
     {
         if ($this->started === false && $this->canBeResumed()) {
+            if (!$this->sessionMetaData) {
+                throw new \Exception('Cannot resume a session without metadata');
+            }
             $this->started = true;
 
             $sessionObjects = $this->sessionKeyValueStore->retrieve($this->sessionMetaData->storageIdentifier, self::FLOW_OBJECT_STORAGE_KEY);
@@ -256,7 +277,7 @@ public function resume(): ?int
      */
     public function getId(): string
     {
-        if ($this->started !== true) {
+        if ($this->started !== true || !$this->sessionMetaData) {
             throw new Exception\SessionNotStartedException('Tried to retrieve the session identifier, but the session has not been started yet.)', 1351171517);
         }
         return $this->sessionMetaData->sessionIdentifier->value;
@@ -276,6 +297,12 @@ public function renewId(): string
         if ($this->started !== true) {
             throw new Exception\SessionNotStartedException('Tried to renew the session identifier, but the session has not been started yet.', 1351182429);
         }
+        if (!$this->sessionMetaData) {
+            throw new \Exception('Missing session metadata');
+        }
+        if (!$this->sessionCookie) {
+            throw new \Exception('Missing session cookie');
+        }
         if ($this->remote === true) {
             throw new Exception\OperationNotSupportedException(sprintf('Tried to renew the session identifier on a remote session (%s).', $this->sessionMetaData->sessionIdentifier->value), 1354034230);
         }
@@ -284,6 +311,12 @@ public function renewId(): string
         $this->sessionMetaData = $this->sessionMetaData->withNewSessionIdentifier();
         $this->writeSessionMetaDataCacheEntry();
 
+        if (!$this->sessionMetaData) {
+            throw new \Exception('Missing session metadata');
+        }
+        if (!$this->sessionCookie) {
+            throw new \Exception('Missing session cookie');
+        }
         $this->sessionCookie->setValue($this->sessionMetaData->sessionIdentifier->value);
         return $this->sessionMetaData->sessionIdentifier->value;
     }
@@ -297,7 +330,7 @@ public function renewId(): string
      */
     public function getData(string $key): mixed
     {
-        if ($this->started !== true) {
+        if ($this->started !== true || !$this->sessionMetaData) {
             throw new Exception\SessionNotStartedException('Tried to get session data, but the session has not been started yet.', 1351162255);
         }
         return $this->sessionKeyValueStore->retrieve($this->sessionMetaData->storageIdentifier, $key);
@@ -312,7 +345,7 @@ public function getData(string $key): mixed
      */
     public function hasKey(string $key): bool
     {
-        if ($this->started !== true) {
+        if ($this->started !== true || !$this->sessionMetaData) {
             throw new Exception\SessionNotStartedException('Tried to check a session data entry, but the session has not been started yet.', 1352488661);
         }
         return $this->sessionKeyValueStore->has($this->sessionMetaData->storageIdentifier, $key);
@@ -332,7 +365,7 @@ public function hasKey(string $key): bool
      */
     public function putData(string $key, mixed $data): void
     {
-        if ($this->started !== true) {
+        if ($this->started !== true || !$this->sessionMetaData) {
             throw new Exception\SessionNotStartedException('Tried to create a session data entry, but the session has not been started yet.', 1351162259);
         }
         if (is_resource($data)) {
@@ -354,7 +387,7 @@ public function putData(string $key, mixed $data): void
      */
     public function getLastActivityTimestamp(): int
     {
-        if ($this->started !== true) {
+        if ($this->started !== true || !$this->sessionMetaData) {
             throw new Exception\SessionNotStartedException('Tried to retrieve the last activity timestamp of a session which has not been started yet.', 1354290378);
         }
         return $this->sessionMetaData->lastActivityTimestamp;
@@ -378,9 +411,9 @@ public function addTag(string $tag): void
             throw new Exception\SessionNotStartedException('Tried to tag a session which has not been started yet.', 1355143533);
         }
         if (!$this->sessionMetaDataStore->isValidSessionTag($tag)) {
-            throw new \InvalidArgumentException(sprintf('The tag used for tagging session %s contained invalid characters. Make sure it matches this regular expression: "%s"', $this->sessionMetaData->sessionIdentifier->value, FrontendInterface::PATTERN_TAG));
+            throw new \InvalidArgumentException(sprintf('The tag used for tagging session %s contained invalid characters. Make sure it matches this regular expression: "%s"', $this->sessionMetaData?->sessionIdentifier->value ?: '', FrontendInterface::PATTERN_TAG));
         }
-        $this->sessionMetaData = $this->sessionMetaData->withAddedTag($tag);
+        $this->sessionMetaData = $this->sessionMetaData?->withAddedTag($tag);
     }
 
     /**
@@ -396,14 +429,14 @@ public function removeTag(string $tag): void
         if ($this->started !== true) {
             throw new Exception\SessionNotStartedException('Tried to tag a session which has not been started yet.', 1355150140);
         }
-        $this->sessionMetaData = $this->sessionMetaData->withRemovedTag($tag);
+        $this->sessionMetaData = $this->sessionMetaData?->withRemovedTag($tag);
     }
 
 
     /**
      * Returns the tags this session has been tagged with.
      *
-     * @return array The tags or an empty array if there aren't any
+     * @return array<string> The tags or an empty array if there aren't any
      * @throws Exception\SessionNotStartedException
      * @api
      */
@@ -412,7 +445,7 @@ public function getTags(): array
         if ($this->started !== true) {
             throw new Exception\SessionNotStartedException('Tried to retrieve tags from a session which has not been started yet.', 1355141501);
         }
-        return $this->sessionMetaData->tags;
+        return $this->sessionMetaData?->tags ?: [];
     }
 
     /**
@@ -428,7 +461,7 @@ public function touch(): void
 
         // Only makes sense for remote sessions because the currently active session
         // will be updated on shutdown anyway:
-        if ($this->remote === true) {
+        if ($this->remote === true && $this->sessionMetaData) {
             $this->sessionMetaData = $this->sessionMetaData->withLastActivityTimestamp($this->now);
             $this->writeSessionMetaDataCacheEntry();
         }
@@ -461,12 +494,14 @@ public function destroy(?string $reason = null): void
         }
 
         if ($this->remote !== true) {
-            $this->sessionCookie->expire();
+            $this->sessionCookie?->expire();
         }
 
-        $this->sessionMetaDataStore->remove($this->sessionMetaData);
-        $this->sessionKeyValueStore->remove($this->sessionMetaData->storageIdentifier);
-        $this->sessionMetaData = null;
+        if ($this->sessionMetaData) {
+            $this->sessionMetaDataStore->remove($this->sessionMetaData);
+            $this->sessionKeyValueStore->remove($this->sessionMetaData->storageIdentifier);
+            $this->sessionMetaData = null;
+        }
         $this->started = false;
     }
 
@@ -482,8 +517,12 @@ public function destroy(?string $reason = null): void
     public function shutdownObject(): void
     {
         if ($this->started === true && $this->remote === false) {
-            if ($this->sessionMetaDataStore->has($this->sessionMetaData->sessionIdentifier)) {
-                $this->sessionKeyValueStore->store($this->sessionMetaData->storageIdentifier, self::FLOW_OBJECT_STORAGE_KEY, $this->objectManager->getSessionInstances() ?? []);
+            if ($this->sessionMetaData && $this->sessionMetaDataStore->has($this->sessionMetaData->sessionIdentifier)) {
+                $this->sessionKeyValueStore->store(
+                    $this->sessionMetaData->storageIdentifier,
+                    self::FLOW_OBJECT_STORAGE_KEY,
+                    $this->objectManager->getSessionInstances()
+                );
                 $this->writeSessionMetaDataCacheEntry();
             }
             $this->started = false;
@@ -497,11 +536,11 @@ public function shutdownObject(): void
      */
     protected function autoExpire(): bool
     {
-        $lastActivitySecondsAgo = $this->now - $this->sessionMetaData->lastActivityTimestamp;
+        $lastActivitySecondsAgo = $this->now - ($this->sessionMetaData?->lastActivityTimestamp ?: 0);
         $expired = false;
         if ($this->inactivityTimeout !== 0 && $lastActivitySecondsAgo > $this->inactivityTimeout) {
             $this->started = true;
-            $this->destroy(sprintf('Session %s was inactive for %s seconds, more than the configured timeout of %s seconds.', $this->sessionMetaData->sessionIdentifier->value, $lastActivitySecondsAgo, $this->inactivityTimeout));
+            $this->destroy(sprintf('Session %s was inactive for %s seconds, more than the configured timeout of %s seconds.', $this->sessionMetaData?->sessionIdentifier->value ?: '', $lastActivitySecondsAgo, $this->inactivityTimeout));
             $expired = true;
         }
         return $expired;
@@ -521,6 +560,8 @@ protected function autoExpire(): bool
      */
     protected function writeSessionMetaDataCacheEntry(): void
     {
-        $this->sessionMetaDataStore->store($this->sessionMetaData);
+        if ($this->sessionMetaData) {
+            $this->sessionMetaDataStore->store($this->sessionMetaData);
+        }
     }
 }
diff --git a/Neos.Flow/Classes/Session/SessionInterface.php b/Neos.Flow/Classes/Session/SessionInterface.php
index 791f21debf..b9c8b51485 100644
--- a/Neos.Flow/Classes/Session/SessionInterface.php
+++ b/Neos.Flow/Classes/Session/SessionInterface.php
@@ -107,7 +107,7 @@ public function removeTag(string $tag): void;
     /**
      * Returns the tags this session has been tagged with.
      *
-     * @return array The tags or an empty array if there aren't any
+     * @return array<string> The tags or an empty array if there aren't any
      * @throws Exception\SessionNotStartedException
      * @api
      */
diff --git a/Neos.Flow/Classes/Session/SessionManager.php b/Neos.Flow/Classes/Session/SessionManager.php
index cdf8d89a90..c6629baccd 100644
--- a/Neos.Flow/Classes/Session/SessionManager.php
+++ b/Neos.Flow/Classes/Session/SessionManager.php
@@ -27,6 +27,10 @@
 class SessionManager implements SessionManagerInterface
 {
     protected ?SessionInterface $currentSession = null;
+
+    /**
+     * @var array<string,Session>
+     */
     protected array $remoteSessions = [];
 
     public function __construct(
@@ -139,7 +143,7 @@ public function getActiveSessions(): array
      * Returns all sessions which are tagged by the specified tag.
      *
      * @param string $tag A valid Cache Frontend tag
-     * @return array A collection of Session objects or an empty array if tag did not match
+     * @return array<SessionInterface> A collection of Session objects or an empty array if tag did not match
      * @throws NotSupportedByBackendException
      * @api
      */
@@ -195,10 +199,8 @@ public function collectGarbage(): ?int
         foreach ($this->sessionMetaDataStore->retrieveAll() as $sessionMetadata) {
             $lastActivitySecondsAgo = $now - $sessionMetadata->lastActivityTimestamp;
             if ($lastActivitySecondsAgo > $this->inactivityTimeout) {
-                if ($sessionMetadata->lastActivityTimestamp !== null) {
-                    $this->sessionKeyValueStore->remove($sessionMetadata->storageIdentifier);
-                    $sessionRemovalCount++;
-                }
+                $this->sessionKeyValueStore->remove($sessionMetadata->storageIdentifier);
+                $sessionRemovalCount++;
                 $this->sessionMetaDataStore->remove($sessionMetadata);
             }
             if ($sessionRemovalCount >= $this->garbageCollectionMaximumPerRun) {
@@ -223,7 +225,7 @@ public function collectGarbage(): ?int
     public function shutdownObject(): void
     {
         if (str_contains((string)$this->garbageCollectionProbability, '.')) {
-            $decimals = strlen(strrchr((string)$this->garbageCollectionProbability, '.')) - 1;
+            $decimals = strlen(strrchr((string)$this->garbageCollectionProbability, '.') ?: '') - 1;
             $factor = $decimals * 10;
         } else {
             $factor = 1;
diff --git a/Neos.Flow/Classes/Session/SessionManagerInterface.php b/Neos.Flow/Classes/Session/SessionManagerInterface.php
index de71da87fd..1455968e47 100644
--- a/Neos.Flow/Classes/Session/SessionManagerInterface.php
+++ b/Neos.Flow/Classes/Session/SessionManagerInterface.php
@@ -51,7 +51,7 @@ public function getActiveSessions(): array;
      * Returns all sessions which are tagged by the specified tag.
      *
      * @param string $tag A valid Cache Frontend tag
-     * @return array A collection of Session objects or an empty array if tag did not match
+     * @return array<SessionInterface> A collection of Session objects or an empty array if tag did not match
      * @api
      */
     public function getSessionsByTag(string $tag): array;
diff --git a/Neos.Flow/Classes/Session/TransientSession.php b/Neos.Flow/Classes/Session/TransientSession.php
index 0e15bb8231..815184ea8a 100644
--- a/Neos.Flow/Classes/Session/TransientSession.php
+++ b/Neos.Flow/Classes/Session/TransientSession.php
@@ -26,8 +26,14 @@ class TransientSession implements SessionInterface
 {
     protected string $sessionId;
     protected bool $started = false;
+    /**
+     * @var array<string,mixed>
+     */
     protected array $data = [];
     protected ?int $lastActivityTimestamp = null;
+    /**
+     * @var array<string,bool>
+     */
     protected array $tags;
 
     public function isStarted(): bool
@@ -165,6 +171,7 @@ public function getLastActivityTimestamp(): int
         if ($this->lastActivityTimestamp === null) {
             $this->touch();
         }
+        /** @phpstan-ignore return.type (touch() initializes the timestamp) */
         return $this->lastActivityTimestamp;
     }
 
@@ -217,7 +224,7 @@ public function removeTag(string $tag): void
     /**
      * Returns the tags this session has been tagged with.
      *
-     * @return array The tags or an empty array if there aren't any
+     * @return array<int,string> The tags or an empty array if there aren't any
      * @throws Exception\SessionNotStartedException
      * @api
      */
diff --git a/Neos.Flow/Classes/SignalSlot/Dispatcher.php b/Neos.Flow/Classes/SignalSlot/Dispatcher.php
index b802e14517..45331881f0 100644
--- a/Neos.Flow/Classes/SignalSlot/Dispatcher.php
+++ b/Neos.Flow/Classes/SignalSlot/Dispatcher.php
@@ -24,18 +24,21 @@
  */
 class Dispatcher
 {
-    /**
-     * @var ObjectManagerInterface
-     */
-    protected $objectManager;
+    protected ?ObjectManagerInterface $objectManager = null;
 
     /**
      * Information about all slots connected a certain signal.
      * Indexed by [$signalClassName][$signalMethodName] and then numeric with an
      * array of information about the slot
-     * @var array
+     * @var array<class-string,array<string,array<int,array{
+     *     class: ?class-string,
+     *     method: string,
+     *     object: ?object,
+     *     passSignalInformation: bool,
+     *     useSignalInformationObject: bool,
+     * }>>>
      */
-    protected $slots = [];
+    protected array $slots = [];
 
     /**
      * Injects the object manager
@@ -56,7 +59,7 @@ public function injectObjectManager(ObjectManagerInterface $objectManager): void
      * When $passSignalInformation is true, the slot will be passed a string (EmitterClassName::signalName) as the last
      * parameter.
      *
-     * @param string $signalClassName Name of the class containing the signal
+     * @param class-string $signalClassName Name of the class containing the signal
      * @param string $signalName Name of the signal
      * @param mixed $slotClassNameOrObject Name of the class containing the slot or the instantiated class or a Closure object
      * @param string $slotMethodName Name of the method to be used as a slot. If $slotClassNameOrObject is a Closure object, this parameter is ignored
@@ -78,7 +81,7 @@ public function connect(string $signalClassName, string $signalName, $slotClassN
      *
      * The slot will be passed a an instance of SignalInformation as the sole parameter.
      *
-     * @param string $signalClassName Name of the class containing the signal
+     * @param class-string $signalClassName Name of the class containing the signal
      * @param string $signalName Name of the signal
      * @param mixed $slotClassNameOrObject Name of the class containing the slot or the instantiated class or a Closure object
      * @param string $slotMethodName Name of the method to be used as a slot. If $slotClassNameOrObject is a Closure object, this parameter is ignored
@@ -94,7 +97,7 @@ public function wire(string $signalClassName, string $signalName, $slotClassName
     }
 
     /**
-     * @param string $signalClassName
+     * @param class-string $signalClassName
      * @param string $signalName
      * @param mixed $slotClassNameOrObject
      * @param string $slotMethodName
@@ -116,6 +119,9 @@ private function connectSignalToSlot(string $signalClassName, string $signalName
             $object = $slotClassNameOrObject;
             $method = ($slotClassNameOrObject instanceof \Closure) ? '__invoke' : $slotMethodName;
         } else {
+            if (!class_exists($slotClassNameOrObject)) {
+                throw new \Exception('Unkown class ' . $slotClassNameOrObject, 1743926351);
+            }
             if ($slotMethodName === '') {
                 throw new \InvalidArgumentException('The slot method name must not be empty (except for closures).', 1229531659);
             }
@@ -137,7 +143,7 @@ private function connectSignalToSlot(string $signalClassName, string $signalName
      *
      * @param string $signalClassName Name of the class containing the signal
      * @param string $signalName Name of the signal
-     * @param array $signalArguments arguments passed to the signal method
+     * @param array<mixed> $signalArguments arguments passed to the signal method
      * @return void
      * @throws Exception\InvalidSlotException if the slot is not valid
      * @api
@@ -153,37 +159,48 @@ public function dispatch(string $signalClassName, string $signalName, array $sig
             if (isset($slotInformation['object'])) {
                 $object = $slotInformation['object'];
             } elseif (strpos($slotInformation['method'], '::') === 0) {
-                if (!isset($this->objectManager)) {
+                if ($this->objectManager === null) {
                     if (is_callable($slotInformation['class'] . $slotInformation['method'])) {
                         $object = $slotInformation['class'];
                     } else {
                         throw new Exception\InvalidSlotException(sprintf('Cannot dispatch %s::%s to class %s. The object manager is not yet available in the Signal Slot Dispatcher and therefore it cannot dispatch classes.', $signalClassName, $signalName, $slotInformation['class']), 1298113624);
                     }
                 } else {
+                    if ($slotInformation['class'] === null) {
+                        throw new Exception\InvalidSlotException('Slot class is undefined.', 1743958214);
+                    }
                     $object = $this->objectManager->getClassNameByObjectName($slotInformation['class']);
                 }
                 $slotInformation['method'] = substr($slotInformation['method'], 2);
             } else {
-                if (!isset($this->objectManager)) {
+                if ($this->objectManager === null) {
                     throw new Exception\InvalidSlotException(sprintf('Cannot dispatch %s::%s to class %s. The object manager is not yet available in the Signal Slot Dispatcher and therefore it cannot dispatch classes.', $signalClassName, $signalName, $slotInformation['class']), 1298113624);
                 }
+                if ($slotInformation['class'] === null) {
+                    throw new Exception\InvalidSlotException('Slot class is undefined.', 1743958214);
+                }
                 if (!$this->objectManager->isRegistered($slotInformation['class'])) {
                     throw new Exception\InvalidSlotException('The given class "' . $slotInformation['class'] . '" is not a registered object.', 1245673367);
                 }
                 $object = $this->objectManager->get($slotInformation['class']);
             }
-            if (!method_exists($object, $slotInformation['method'])) {
+            if (is_object($object) && !method_exists($object, $slotInformation['method'])) {
                 throw new Exception\InvalidSlotException('The slot method ' . get_class($object) . '->' . $slotInformation['method'] . '() does not exist.', 1245673368);
             }
 
+            $callable = [$object, $slotInformation['method']];
+            if (!is_callable($callable)) {
+                throw new \Exception('Invalid slot method ' . $slotInformation['method'], 1743955562);
+            }
+
             if ($slotInformation['useSignalInformationObject'] === true) {
-                call_user_func([$object, $slotInformation['method']], new SignalInformation($signalClassName, $signalName, $finalSignalArguments));
+                call_user_func($callable, new SignalInformation($signalClassName, $signalName, $finalSignalArguments));
             } else {
                 if ($slotInformation['passSignalInformation'] === true) {
                     $finalSignalArguments[] = $signalClassName . '::' . $signalName;
                 }
                 // Need to use call_user_func_array here, because $object may be the class name when the slot is a static method
-                call_user_func_array([$object, $slotInformation['method']], $finalSignalArguments);
+                call_user_func_array($callable, $finalSignalArguments);
             }
         }
     }
@@ -191,9 +208,15 @@ public function dispatch(string $signalClassName, string $signalName, array $sig
     /**
      * Returns all slots which are connected with the given signal
      *
-     * @param string $signalClassName Name of the class containing the signal
+     * @param class-string $signalClassName Name of the class containing the signal
      * @param string $signalName Name of the signal
-     * @return array An array of arrays with slot information
+     * @return array<int,array{
+     *      class: ?class-string,
+     *      method: string,
+     *      object: ?object,
+     *      passSignalInformation: bool,
+     *      useSignalInformationObject: bool,
+     *  }> An array of arrays with slot information
      * @api
      */
     public function getSlots(string $signalClassName, string $signalName): array
@@ -204,7 +227,13 @@ public function getSlots(string $signalClassName, string $signalName): array
     /**
      * Returns all signals with its slots
      *
-     * @return array An array of arrays with slot information
+     * @return array<class-string,array<string,array<int,array{
+     *      class: ?class-string,
+     *      method: string,
+     *      object: ?object,
+     *      passSignalInformation: bool,
+     *      useSignalInformationObject: bool,
+     *  }>>> An array of arrays with slot information
      * @api
      */
     public function getSignals(): array
diff --git a/Neos.Flow/Classes/SignalSlot/SignalInformation.php b/Neos.Flow/Classes/SignalSlot/SignalInformation.php
index 650b133a76..3ad58347bc 100644
--- a/Neos.Flow/Classes/SignalSlot/SignalInformation.php
+++ b/Neos.Flow/Classes/SignalSlot/SignalInformation.php
@@ -35,10 +35,13 @@ final class SignalInformation
     protected $signalName;
 
     /**
-     * @var array
+     * @var array<mixed>
      */
     protected $signalArguments;
 
+    /**
+     * @param array<mixed> $signalArguments
+     */
     public function __construct(string $signalClassName, string $signalName, array $signalArguments)
     {
         $this->signalClassName = $signalClassName;
@@ -56,6 +59,9 @@ public function getSignalName(): string
         return $this->signalName;
     }
 
+    /**
+     * @return array<mixed>
+     */
     public function getSignalArguments(): array
     {
         return $this->signalArguments;
diff --git a/Neos.Flow/Classes/Utility/Algorithms.php b/Neos.Flow/Classes/Utility/Algorithms.php
index 9991b4cfe4..fb46608466 100644
--- a/Neos.Flow/Classes/Utility/Algorithms.php
+++ b/Neos.Flow/Classes/Utility/Algorithms.php
@@ -36,7 +36,7 @@ class Algorithms
      */
     public static function generateUUID(): string
     {
-        if (is_callable('uuid_create')) {
+        if (function_exists('uuid_create')) {
             return strtolower(uuid_create(UUID_TYPE_RANDOM));
         }
 
diff --git a/Neos.Flow/Classes/Utility/Environment.php b/Neos.Flow/Classes/Utility/Environment.php
index 44787d3f87..28845bb93f 100644
--- a/Neos.Flow/Classes/Utility/Environment.php
+++ b/Neos.Flow/Classes/Utility/Environment.php
@@ -140,18 +140,15 @@ public static function composeTemporaryDirectoryName(string $temporaryDirectoryB
      *
      * @param string $temporaryDirectoryBase Full path to the base for the temporary directory
      * @return string The full path to the temporary directory
-     * @throws UtilityException if the temporary directory could not be created or is not writable
+     * @throws FilesException if the temporary directory could not be created
+     * @throws UtilityException if the temporary directory is not writable
      */
     protected function createTemporaryDirectory(string $temporaryDirectoryBase): string
     {
         $temporaryDirectory = self::composeTemporaryDirectoryName($temporaryDirectoryBase, $this->context);
 
         if (!is_dir($temporaryDirectory) && !is_link($temporaryDirectory)) {
-            try {
-                Files::createDirectoryRecursively($temporaryDirectory);
-            } catch (ErrorException $exception) {
-                throw new UtilityException('The temporary directory "' . $temporaryDirectory . '" could not be created. Please make sure permissions are correct for this path or define another temporary directory in your Settings.yaml with the path "Neos.Flow.utility.environment.temporaryDirectoryBase".', 1335382361);
-            }
+            Files::createDirectoryRecursively($temporaryDirectory);
         }
 
         if (!is_writable($temporaryDirectory)) {
diff --git a/Neos.Flow/Classes/Validation/Validator/AbstractCompositeValidator.php b/Neos.Flow/Classes/Validation/Validator/AbstractCompositeValidator.php
index 4803782fa4..dba8d72acb 100644
--- a/Neos.Flow/Classes/Validation/Validator/AbstractCompositeValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/AbstractCompositeValidator.php
@@ -24,29 +24,29 @@ abstract class AbstractCompositeValidator implements ObjectValidatorInterface, \
     /**
      * This contains the supported options, their default values and descriptions.
      *
-     * @var array
+     * @var array<mixed>
      */
     protected $supportedOptions = [];
 
     /**
-     * @var array
+     * @var array<mixed>
      */
     protected $options = [];
 
     /**
-     * @var \SplObjectStorage
+     * @var \SplObjectStorage<ValidatorInterface,mixed>
      */
     protected $validators;
 
     /**
-     * @var \SplObjectStorage
+     * @var \SplObjectStorage<object,mixed>
      */
     protected $validatedInstancesContainer;
 
     /**
      * Constructs the composite validator and sets validation options
      *
-     * @param array $options Options for the validator
+     * @param array<mixed> $options Options for the validator
      * @api
      * @throws InvalidValidationOptionsException
      */
@@ -84,7 +84,7 @@ function ($value) {
     /**
      * Allows to set a container to keep track of validated instances.
      *
-     * @param \SplObjectStorage $validatedInstancesContainer A container to keep track of validated instances
+     * @param \SplObjectStorage<object,mixed> $validatedInstancesContainer A container to keep track of validated instances
      * @return void
      * @api
      */
@@ -102,7 +102,7 @@ public function setValidatedInstancesContainer(\SplObjectStorage $validatedInsta
      */
     public function addValidator(ValidatorInterface $validator)
     {
-        if ($validator instanceof ObjectValidatorInterface && isset($this->validatedInstancesContainer)) {
+        if ($validator instanceof ObjectValidatorInterface) {
             $validator->setValidatedInstancesContainer($this->validatedInstancesContainer);
         }
         $this->validators->attach($validator);
@@ -115,7 +115,7 @@ public function addValidator(ValidatorInterface $validator)
      * @throws NoSuchValidatorException
      * @api
      */
-    public function removeValidator(ValidatorInterface $validator)
+    public function removeValidator(ValidatorInterface $validator): void
     {
         if (!$this->validators->contains($validator)) {
             throw new NoSuchValidatorException('Cannot remove validator because its not in the conjunction.', 1207020177);
@@ -137,7 +137,7 @@ public function count(): int
     /**
      * Returns the child validators of this Composite Validator
      *
-     * @return \SplObjectStorage
+     * @return \SplObjectStorage<ValidatorInterface,mixed>
      */
     public function getValidators()
     {
@@ -147,7 +147,7 @@ public function getValidators()
     /**
      * Returns the options for this validator
      *
-     * @return array
+     * @return array<mixed>
      */
     public function getOptions()
     {
diff --git a/Neos.Flow/Classes/Validation/Validator/AbstractValidator.php b/Neos.Flow/Classes/Validation/Validator/AbstractValidator.php
index 7a11ff35e9..9f91868935 100644
--- a/Neos.Flow/Classes/Validation/Validator/AbstractValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/AbstractValidator.php
@@ -41,17 +41,17 @@ abstract class AbstractValidator implements ValidatorInterface
      * 2 => type
      * 3 => required (boolean, optional)
      *
-     * @var array
+     * @var array<mixed>
      */
     protected $supportedOptions = [];
 
     /**
-     * @var array
+     * @var array<mixed>
      */
     protected $options = [];
 
     /**
-     * @var ErrorResult
+     * @var ErrorResult|null
      */
     private $result;
 
@@ -63,7 +63,7 @@ abstract class AbstractValidator implements ValidatorInterface
     /**
      * Constructs the validator and sets validation options
      *
-     * @param array $options Options for the validator
+     * @param array<mixed> $options Options for the validator
      * @throws InvalidValidationOptionsException if unsupported options are found
      * @api
      */
@@ -117,7 +117,7 @@ protected function pushResult()
     /**
      * Pop and return the current Result from the stack and make $this->result point to the last Result again.
      * @since Flow 4.3
-     * @return ErrorResult
+     * @return ErrorResult|null
      */
     protected function popResult()
     {
@@ -143,7 +143,7 @@ protected function getResult()
      * the Error Messages object which occurred.
      *
      * @param mixed $value The value that should be validated
-     * @return ErrorResult
+     * @return ErrorResult|null
      * @throws InvalidValidationOptionsException
      * @api
      */
@@ -171,19 +171,22 @@ abstract protected function isValid($value);
      *
      * @param string $message The error message
      * @param integer $code The error code (a unix timestamp)
-     * @param array $arguments Arguments to be replaced in message
+     * @param array<mixed> $arguments Arguments to be replaced in message
      * @return void
      * @api
      */
     protected function addError($message, $code, array $arguments = [])
     {
+        if ($this->result === null) {
+            $this->result = new ErrorResult();
+        }
         $this->result->addError(new ValidationError($message, $code, $arguments));
     }
 
     /**
      * Returns the options of this validator
      *
-     * @return array
+     * @return array<mixed>
      */
     public function getOptions()
     {
diff --git a/Neos.Flow/Classes/Validation/Validator/BooleanValueValidator.php b/Neos.Flow/Classes/Validation/Validator/BooleanValueValidator.php
index be9ac2833f..c0d773440c 100644
--- a/Neos.Flow/Classes/Validation/Validator/BooleanValueValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/BooleanValueValidator.php
@@ -22,7 +22,7 @@
 class BooleanValueValidator extends AbstractValidator
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'expectedValue' => [true, 'The expected boolean value', 'boolean']
diff --git a/Neos.Flow/Classes/Validation/Validator/CollectionValidator.php b/Neos.Flow/Classes/Validation/Validator/CollectionValidator.php
index e02bf51efb..85376bc5ca 100644
--- a/Neos.Flow/Classes/Validation/Validator/CollectionValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/CollectionValidator.php
@@ -22,7 +22,7 @@
 class CollectionValidator extends GenericObjectValidator
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'elementValidator' => [null, 'The validator type to use for the collection elements', 'string'],
@@ -52,7 +52,7 @@ protected function isValid($value)
     {
         if ($value instanceof \Doctrine\Common\Collections\AbstractLazyCollection && !$value->isInitialized()) {
             return;
-        } elseif ((is_object($value) && !TypeHandling::isCollectionType(get_class($value))) && !is_array($value)) {
+        } elseif (is_object($value) && !TypeHandling::isCollectionType(get_class($value))) {
             $this->addError('The given subject was not a collection.', 1317204797);
             return;
         } elseif (is_object($value) && $this->isValidatedAlready($value)) {
@@ -75,7 +75,9 @@ protected function isValid($value)
                 $collectionElementValidator->setValidatedInstancesContainer($this->validatedInstancesContainer);
             }
 
-            $this->getResult()->forProperty($index)->merge($collectionElementValidator->validate($collectionElement));
+            if ($this->getResult() && $collectionElementValidator) {
+                $this->getResult()->forProperty($index)->merge($collectionElementValidator->validate($collectionElement));
+            }
         }
     }
 }
diff --git a/Neos.Flow/Classes/Validation/Validator/ConjunctionValidator.php b/Neos.Flow/Classes/Validation/Validator/ConjunctionValidator.php
index 1dc9ff520b..c2bbd67562 100644
--- a/Neos.Flow/Classes/Validation/Validator/ConjunctionValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/ConjunctionValidator.php
@@ -25,7 +25,7 @@ class ConjunctionValidator extends AbstractCompositeValidator
      * Every validator has to be valid, to make the whole conjunction valid.
      *
      * @param mixed $value The value that should be validated
-     * @return ErrorResult
+     * @return ErrorResult|null
      * @api
      */
     public function validate($value)
diff --git a/Neos.Flow/Classes/Validation/Validator/CountValidator.php b/Neos.Flow/Classes/Validation/Validator/CountValidator.php
index 97a2b8cc7d..9e80afb73e 100644
--- a/Neos.Flow/Classes/Validation/Validator/CountValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/CountValidator.php
@@ -20,7 +20,7 @@
 class CountValidator extends AbstractValidator
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'minimum' => [0, 'The minimum count to accept', 'integer'],
diff --git a/Neos.Flow/Classes/Validation/Validator/DateTimeRangeValidator.php b/Neos.Flow/Classes/Validation/Validator/DateTimeRangeValidator.php
index cf5266d104..1e9a2fece4 100644
--- a/Neos.Flow/Classes/Validation/Validator/DateTimeRangeValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/DateTimeRangeValidator.php
@@ -21,7 +21,7 @@
 class DateTimeRangeValidator extends AbstractValidator
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'latestDate' => [null, 'The latest date to accept', 'string'],
diff --git a/Neos.Flow/Classes/Validation/Validator/DateTimeValidator.php b/Neos.Flow/Classes/Validation/Validator/DateTimeValidator.php
index db14ba9293..ebd10f2c2d 100644
--- a/Neos.Flow/Classes/Validation/Validator/DateTimeValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/DateTimeValidator.php
@@ -23,7 +23,7 @@
 class DateTimeValidator extends AbstractValidator
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'locale' => [null, 'The locale to use for date parsing', 'string|Locale'],
diff --git a/Neos.Flow/Classes/Validation/Validator/DisjunctionValidator.php b/Neos.Flow/Classes/Validation/Validator/DisjunctionValidator.php
index 605a2c69c5..6373ac2c47 100644
--- a/Neos.Flow/Classes/Validation/Validator/DisjunctionValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/DisjunctionValidator.php
@@ -28,7 +28,7 @@ class DisjunctionValidator extends AbstractCompositeValidator
      * Errors are only returned if all validators failed.
      *
      * @param mixed $value The value that should be validated
-     * @return ErrorResult
+     * @return ErrorResult|null
      * @api
      */
     public function validate($value)
diff --git a/Neos.Flow/Classes/Validation/Validator/EmailAddressValidator.php b/Neos.Flow/Classes/Validation/Validator/EmailAddressValidator.php
index bf9609d4cb..2d814e1bc8 100644
--- a/Neos.Flow/Classes/Validation/Validator/EmailAddressValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/EmailAddressValidator.php
@@ -27,7 +27,7 @@
 class EmailAddressValidator extends AbstractValidator
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'strict' => [false, 'Whether to fail validation on RFC warnings', 'bool'],
diff --git a/Neos.Flow/Classes/Validation/Validator/FileExtensionValidator.php b/Neos.Flow/Classes/Validation/Validator/FileExtensionValidator.php
index c3534f7ff4..fd72ac0bb5 100644
--- a/Neos.Flow/Classes/Validation/Validator/FileExtensionValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/FileExtensionValidator.php
@@ -31,7 +31,7 @@ class FileExtensionValidator extends AbstractValidator
      * 2 => type
      * 3 => required (boolean, optional)
      *
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'allowedExtensions' => [[], 'Array of allowed file extensions', 'array', true]
@@ -58,9 +58,9 @@ protected function isValid($value)
             return;
         }
 
-        $fileExtension =  pathinfo((string)$filename, PATHINFO_EXTENSION);
+        $fileExtension = pathinfo((string)$filename, PATHINFO_EXTENSION);
 
-        if ($fileExtension === null || $fileExtension === '') {
+        if ($fileExtension === '') {
             $this->addError('The file has no file extension.', 1677934932);
             return;
         }
diff --git a/Neos.Flow/Classes/Validation/Validator/FileSizeValidator.php b/Neos.Flow/Classes/Validation/Validator/FileSizeValidator.php
index 13283f7624..7507d821ad 100644
--- a/Neos.Flow/Classes/Validation/Validator/FileSizeValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/FileSizeValidator.php
@@ -31,7 +31,7 @@ class FileSizeValidator extends AbstractValidator
      * 2 => type
      * 3 => required (boolean, optional)
      *
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'minimum' => [null, 'Minimum allowed filesize in bytes', 'integer', false],
diff --git a/Neos.Flow/Classes/Validation/Validator/GenericObjectValidator.php b/Neos.Flow/Classes/Validation/Validator/GenericObjectValidator.php
index e211fc144b..bd38927e04 100644
--- a/Neos.Flow/Classes/Validation/Validator/GenericObjectValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/GenericObjectValidator.php
@@ -23,26 +23,26 @@
 class GenericObjectValidator extends AbstractValidator implements ObjectValidatorInterface
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'skipUnInitializedProxies' => [false, 'Whether proxies not yet initialized should be skipped during validation', 'boolean']
     ];
 
     /**
-     * @var array
+     * @var array<string,\SplObjectStorage<ValidatorInterface,mixed>>
      */
     protected $propertyValidators = [];
 
     /**
-     * @var \SplObjectStorage
+     * @var \SplObjectStorage<object,mixed>
      */
     protected $validatedInstancesContainer;
 
     /**
      * Allows to set a container to keep track of validated instances.
      *
-     * @param \SplObjectStorage $validatedInstancesContainer A container to keep track of validated instances
+     * @param \SplObjectStorage<object,mixed> $validatedInstancesContainer A container to keep track of validated instances
      * @return void
      * @api
      */
@@ -77,16 +77,17 @@ protected function isValid($object)
             $propertyValue = $this->getPropertyValue($object, $propertyName);
             $result = $this->checkProperty($propertyValue, $validators);
             if ($result !== null) {
-                $this->getResult()->forProperty($propertyName)->merge($result);
+                if ($this->getResult()) {
+                    $this->getResult()->forProperty($propertyName)->merge($result);
+                }
             }
         }
     }
 
     /**
-     * @param $object
      * @return boolean
      */
-    protected function isUninitializedProxy($object)
+    protected function isUninitializedProxy(object $object)
     {
         return ($object instanceof DoctrineProxy && $object->__isInitialized() === false);
     }
@@ -132,7 +133,7 @@ protected function getPropertyValue($object, $propertyName)
      * found errors to the $messages object.
      *
      * @param mixed $value The value to be validated
-     * @param array $validators The validators to be called on the value
+     * @param array<ValidatorInterface>|\SplObjectStorage<ValidatorInterface,mixed> $validators The validators to be called on the value
      * @return NULL|ErrorResult
      */
     protected function checkProperty($value, $validators)
@@ -162,10 +163,12 @@ protected function checkProperty($value, $validators)
      * @return void
      * @api
      */
-    public function addPropertyValidator($propertyName, ValidatorInterface $validator)
+    public function addPropertyValidator(string $propertyName, ValidatorInterface $validator)
     {
         if (!isset($this->propertyValidators[$propertyName])) {
-            $this->propertyValidators[$propertyName] = new \SplObjectStorage();
+            /** @var \SplObjectStorage<ValidatorInterface,mixed> $storage */
+            $storage = new \SplObjectStorage();
+            $this->propertyValidators[$propertyName] = $storage;
         }
         $this->propertyValidators[$propertyName]->attach($validator);
     }
@@ -173,13 +176,18 @@ public function addPropertyValidator($propertyName, ValidatorInterface $validato
     /**
      * Returns all property validators - or only validators of the specified property
      *
-     * @param string $propertyName Name of the property to return validators for
-     * @return array An array of validators
+     * @param ?string $propertyName Name of the property to return validators for
+     * @return ($propertyName is null ? array<string,\SplObjectStorage<ValidatorInterface,mixed>> : \SplObjectStorage<ValidatorInterface,mixed>)
      */
-    public function getPropertyValidators($propertyName = null)
+    public function getPropertyValidators(?string $propertyName = null)
     {
         if ($propertyName !== null) {
-            return $this->propertyValidators[$propertyName] ?? [];
+            $propertyValidators = $this->propertyValidators[$propertyName] ?? null;
+            if (!$propertyValidators) {
+                /** @var \SplObjectStorage<ValidatorInterface,mixed> $propertyValidators */
+                $propertyValidators = new \SplObjectStorage();
+            }
+            return $propertyValidators;
         }
         return $this->propertyValidators;
     }
diff --git a/Neos.Flow/Classes/Validation/Validator/MediaTypeValidator.php b/Neos.Flow/Classes/Validation/Validator/MediaTypeValidator.php
index 5d0c7b3444..bc519d58c1 100644
--- a/Neos.Flow/Classes/Validation/Validator/MediaTypeValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/MediaTypeValidator.php
@@ -32,7 +32,7 @@ class MediaTypeValidator extends AbstractValidator
      * 2 => type
      * 3 => required (boolean, optional)
      *
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'allowedTypes' => [[], 'Array of allowed media ranges', 'array', true],
diff --git a/Neos.Flow/Classes/Validation/Validator/NumberRangeValidator.php b/Neos.Flow/Classes/Validation/Validator/NumberRangeValidator.php
index ba6c31be92..07a1db9858 100644
--- a/Neos.Flow/Classes/Validation/Validator/NumberRangeValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/NumberRangeValidator.php
@@ -20,7 +20,7 @@
 class NumberRangeValidator extends AbstractValidator
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'minimum' => [0, 'The minimum value to accept', 'integer'],
diff --git a/Neos.Flow/Classes/Validation/Validator/NumberValidator.php b/Neos.Flow/Classes/Validation/Validator/NumberValidator.php
index dd1a7db346..754a497cf9 100644
--- a/Neos.Flow/Classes/Validation/Validator/NumberValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/NumberValidator.php
@@ -23,7 +23,7 @@
 class NumberValidator extends AbstractValidator
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'locale' => [null, 'The locale to use for number parsing', 'string|Locale'],
diff --git a/Neos.Flow/Classes/Validation/Validator/ObjectValidatorInterface.php b/Neos.Flow/Classes/Validation/Validator/ObjectValidatorInterface.php
index 43f27b1a29..e1c3fa30d8 100644
--- a/Neos.Flow/Classes/Validation/Validator/ObjectValidatorInterface.php
+++ b/Neos.Flow/Classes/Validation/Validator/ObjectValidatorInterface.php
@@ -21,7 +21,7 @@ interface ObjectValidatorInterface extends ValidatorInterface
     /**
      * Allows to set a container to keep track of validated instances.
      *
-     * @param \SplObjectStorage $validatedInstancesContainer A container to keep track of validated instances
+     * @param \SplObjectStorage<object, mixed> $validatedInstancesContainer A container to keep track of validated instances
      * @return void
      * @api
      */
diff --git a/Neos.Flow/Classes/Validation/Validator/RegularExpressionValidator.php b/Neos.Flow/Classes/Validation/Validator/RegularExpressionValidator.php
index b2e7ad387b..18cbf52301 100644
--- a/Neos.Flow/Classes/Validation/Validator/RegularExpressionValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/RegularExpressionValidator.php
@@ -21,7 +21,7 @@
 class RegularExpressionValidator extends AbstractValidator
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'regularExpression' => ['', 'The regular expression to use for validation, used as given', 'string', true]
diff --git a/Neos.Flow/Classes/Validation/Validator/StringLengthValidator.php b/Neos.Flow/Classes/Validation/Validator/StringLengthValidator.php
index a48ecd7f19..e99f359400 100644
--- a/Neos.Flow/Classes/Validation/Validator/StringLengthValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/StringLengthValidator.php
@@ -22,7 +22,7 @@
 class StringLengthValidator extends AbstractValidator
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'minimum' => [0, 'Minimum length for a valid string', 'integer'],
diff --git a/Neos.Flow/Classes/Validation/Validator/UniqueEntityValidator.php b/Neos.Flow/Classes/Validation/Validator/UniqueEntityValidator.php
index 83fcb69dd2..ed12067304 100644
--- a/Neos.Flow/Classes/Validation/Validator/UniqueEntityValidator.php
+++ b/Neos.Flow/Classes/Validation/Validator/UniqueEntityValidator.php
@@ -39,7 +39,7 @@ class UniqueEntityValidator extends AbstractValidator
     protected $persistenceManager;
 
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'identityProperties' => [null, 'List of custom identity properties.', 'array']
@@ -60,7 +60,7 @@ protected function isValid($value)
             throw new InvalidValidationOptionsException('The value supplied for the UniqueEntityValidator must be an object.', 1358454270);
         }
 
-        $classSchema = $this->reflectionService->getClassSchema(TypeHandling::getTypeForValue($value));
+        $classSchema = $this->reflectionService->getClassSchema($value);
         if ($classSchema === null || $classSchema->getModelType() !== ClassSchema::MODELTYPE_ENTITY) {
             throw new InvalidValidationOptionsException('The object supplied for the UniqueEntityValidator must be an entity.', 1358454284);
         }
diff --git a/Neos.Flow/Classes/Validation/Validator/ValidatorInterface.php b/Neos.Flow/Classes/Validation/Validator/ValidatorInterface.php
index b142149381..55cd6c4228 100644
--- a/Neos.Flow/Classes/Validation/Validator/ValidatorInterface.php
+++ b/Neos.Flow/Classes/Validation/Validator/ValidatorInterface.php
@@ -41,7 +41,7 @@ public function validate($value);
     /**
      * Returns the options of this validator which can be specified in the constructor
      *
-     * @return array
+     * @return array<mixed>
      */
     public function getOptions();
 }
diff --git a/Neos.Flow/Classes/Validation/ValidatorResolver.php b/Neos.Flow/Classes/Validation/ValidatorResolver.php
index 3400c85715..11a72dffae 100644
--- a/Neos.Flow/Classes/Validation/ValidatorResolver.php
+++ b/Neos.Flow/Classes/Validation/ValidatorResolver.php
@@ -77,7 +77,7 @@ class ValidatorResolver
     protected $reflectionService;
 
     /**
-     * @var array
+     * @var array<string,ConjunctionValidator>
      */
     protected $baseValidatorConjunctions = [];
 
@@ -87,7 +87,7 @@ class ValidatorResolver
      * could be resolved.
      *
      * @param string $validatorType Either one of the built-in data types or fully qualified validator class name
-     * @param array $validatorOptions Options to be passed to the validator
+     * @param array<mixed> $validatorOptions Options to be passed to the validator
      * @return ValidatorInterface|null
      * @throws Exception\NoSuchValidatorException
      * @throws Exception\InvalidValidationConfigurationException
@@ -114,10 +114,6 @@ public function createValidator($validatorType, array $validatorOptions = [])
                 throw new Exception\NoSuchValidatorException('The validator "' . $validatorObjectName . '" is not of scope singleton or prototype!', 1300694835);
         }
 
-        if (!($validator instanceof ValidatorInterface)) {
-            throw new Exception\NoSuchValidatorException(sprintf('The validator "%s" does not implement %s!', $validatorObjectName, ValidatorInterface::class), 1300694875);
-        }
-
         return $validator;
     }
 
@@ -127,7 +123,7 @@ public function createValidator($validatorType, array $validatorOptions = [])
      * If no validation is necessary, the returned validator is empty.
      *
      * @param string $targetClassName Fully qualified class name of the target class, ie. the class which should be validated
-     * @param array $validationGroups The validation groups to build the validator for
+     * @param array<int,string> $validationGroups The validation groups to build the validator for
      * @return ConjunctionValidator The validator conjunction
      * @throws Exception\InvalidValidationConfigurationException
      * @throws Exception\InvalidValidationOptionsException
@@ -150,10 +146,10 @@ public function getBaseValidatorConjunction($targetClassName, array $validationG
      * - by the data type specified in the param annotations
      * - additional validators specified in the validate annotations of a method
      *
-     * @param string $className
+     * @param class-string $className
      * @param string $methodName
-     * @param array $methodParameters Optional pre-compiled array of method parameters
-     * @param array $methodValidateAnnotations Optional pre-compiled array of validate annotations (as array)
+     * @param array<string,mixed>|null $methodParameters Optional pre-compiled array of method parameters
+     * @param array<array{type: ?string, options: array<mixed>, argumentName: string}>|null $methodValidateAnnotations Optional pre-compiled array of validate annotations (as array)
      * @return array<ConjunctionValidator> An Array of ValidatorConjunctions for each method parameters.
      * @throws Exception\InvalidValidationConfigurationException
      * @throws Exception\NoSuchValidatorException
@@ -202,7 +198,11 @@ public function buildMethodArgumentsValidatorConjunctions($className, $methodNam
         }
 
         foreach ($methodValidateAnnotations as $annotationParameters) {
-            $newValidator = $this->createValidator($annotationParameters['type'], $annotationParameters['options']);
+            $validatorType = $annotationParameters['type'] ?? null;
+            if ($validatorType === null) {
+                throw new \Exception('Missing validator type', 1743872674);
+            }
+            $newValidator = $this->createValidator($validatorType, $annotationParameters['options']);
             if ($newValidator === null) {
                 throw new Exception\NoSuchValidatorException('Invalid validate annotation in ' . $className . '->' . $methodName . '(): Could not resolve class name for  validator "' . $annotationParameters['type'] . '".', 1239853109);
             }
@@ -235,7 +235,7 @@ public function reset()
      * Builds a chain of nested object validators by specification of the given
      * object path.
      *
-     * @param array $objectPath The object path
+     * @param array<string> $objectPath The object path
      * @param ValidatorInterface $propertyValidator The validator which should be added to the property specified by objectPath
      * @return GenericObjectValidator
      * @throws Exception\InvalidValidationOptionsException
@@ -252,7 +252,12 @@ protected function buildSubObjectValidator(array $objectPath, ValidatorInterface
             $parentObjectValidator = $subObjectValidator;
         }
 
-        $parentObjectValidator->addPropertyValidator(array_shift($objectPath), $propertyValidator);
+        $propertyName = array_shift($objectPath);
+        if (!is_string($propertyName)) {
+            throw new \Exception('Missing propertyName', 1743872593);
+        }
+
+        $parentObjectValidator->addPropertyValidator($propertyName, $propertyValidator);
 
         return $rootObjectValidator;
     }
@@ -275,7 +280,7 @@ protected function buildSubObjectValidator(array $objectPath, ValidatorInterface
      *
      * @param string $indexKey The key to use as index in $this->baseValidatorConjunctions; calculated from target class name and validation groups
      * @param string $targetClassName The data type to build the validation conjunction for. Needs to be the fully qualified class name.
-     * @param array $validationGroups The validation groups to build the validator for
+     * @param array<int,string> $validationGroups The validation groups to build the validator for
      * @return void
      * @throws Exception\NoSuchValidatorException
      * @throws \InvalidArgumentException
@@ -333,6 +338,9 @@ protected function buildBaseValidatorConjunction($indexKey, $targetClassName, ar
 
                 $validateAnnotations = $this->reflectionService->getPropertyAnnotations($targetClassName, $classPropertyName, Flow\Validate::class);
                 foreach ($validateAnnotations as $validateAnnotation) {
+                    if ($validateAnnotation->type === null) {
+                        continue;
+                    }
                     if ($validateAnnotation->type === 'Collection') {
                         $needsCollectionValidator = false;
                         $validateAnnotation->options = array_merge(['elementType' => $parsedType['elementType'], 'validationGroups' => $validationGroups], $validateAnnotation->options);
@@ -356,7 +364,9 @@ protected function buildBaseValidatorConjunction($indexKey, $targetClassName, ar
 
                 if ($needsCollectionValidator) {
                     $collectionValidator = $this->createValidator(Validator\CollectionValidator::class, ['elementType' => $parsedType['elementType'], 'validationGroups' => $validationGroups]);
-                    $objectValidator->addPropertyValidator($classPropertyName, $collectionValidator);
+                    if ($collectionValidator instanceof ValidatorInterface) {
+                        $objectValidator->addPropertyValidator($classPropertyName, $collectionValidator);
+                    }
                 }
                 if ($needsObjectValidator) {
                     $validatorForProperty = $this->getBaseValidatorConjunction($propertyTargetClassName, $validationGroups);
@@ -424,7 +434,7 @@ protected function addCustomValidators($targetClassName, ConjunctionValidator &$
      * Returns a map of object validator class names.
      *
      * @param ObjectManagerInterface $objectManager
-     * @return array Array of object validator class names
+     * @return list<class-string<PolyTypeObjectValidatorInterface>> Array of object validator class names
      * @Flow\CompileStatic
      */
     public static function getPolyTypeObjectValidatorImplementationClassNames($objectManager)
@@ -439,7 +449,7 @@ public static function getPolyTypeObjectValidatorImplementationClassNames($objec
      * validator is available false is returned
      *
      * @param string $validatorType Either the fully qualified class name of the validator or the short name of a built-in validator
-     * @return string|false Class name of the validator or false if not available
+     * @return class-string<ValidatorInterface>|false Class name of the validator or false if not available
      */
     protected function resolveValidatorObjectName($validatorType)
     {
@@ -448,6 +458,7 @@ protected function resolveValidatorObjectName($validatorType)
         $validatorClassNames = static::getValidatorImplementationClassNames($this->objectManager);
 
         if ($this->objectManager->isRegistered($validatorType) && isset($validatorClassNames[$validatorType])) {
+            /** @var class-string<ValidatorInterface> $validatorType */
             return $validatorType;
         }
 
@@ -458,6 +469,7 @@ protected function resolveValidatorObjectName($validatorType)
             $possibleClassName = sprintf('Neos\Flow\Validation\Validator\%sValidator', $this->getValidatorType($validatorType));
         }
         if ($this->objectManager->isRegistered($possibleClassName) && isset($validatorClassNames[$possibleClassName])) {
+            /** @var class-string<ValidatorInterface> $possibleClassName */
             return $possibleClassName;
         }
 
@@ -468,7 +480,7 @@ protected function resolveValidatorObjectName($validatorType)
      * Returns all class names implementing the ValidatorInterface.
      *
      * @param ObjectManagerInterface $objectManager
-     * @return array Array of class names implementing ValidatorInterface indexed by class name
+     * @return array<class-string<ValidatorInterface>,int> Array of class names implementing ValidatorInterface indexed by class name
      * @Flow\CompileStatic
      */
     public static function getValidatorImplementationClassNames($objectManager)
diff --git a/Neos.FluidAdaptor/Classes/Core/Cache/CacheAdaptor.php b/Neos.FluidAdaptor/Classes/Core/Cache/CacheAdaptor.php
index 43bb16e5a4..a80d47190b 100644
--- a/Neos.FluidAdaptor/Classes/Core/Cache/CacheAdaptor.php
+++ b/Neos.FluidAdaptor/Classes/Core/Cache/CacheAdaptor.php
@@ -50,7 +50,7 @@ public function get($name)
      * @param string $name
      * @param string $value
      */
-    public function set($name, $value)
+    public function set($name, $value): void
     {
         // we need to strip the first line with the php header as the flow cache adds that again.
         $this->flowCache->set($name, substr($value, strpos($value, "\n") + 1));
diff --git a/Neos.FluidAdaptor/Classes/Core/Parser/Interceptor/ResourceInterceptor.php b/Neos.FluidAdaptor/Classes/Core/Parser/Interceptor/ResourceInterceptor.php
index 286870a6ac..9334df24ad 100644
--- a/Neos.FluidAdaptor/Classes/Core/Parser/Interceptor/ResourceInterceptor.php
+++ b/Neos.FluidAdaptor/Classes/Core/Parser/Interceptor/ResourceInterceptor.php
@@ -97,7 +97,7 @@ public function process(NodeInterface $node, $interceptorPosition, ParsingState
         if (strpos($node->getText(), 'Public/') === false) {
             return $node;
         }
-        $textParts = preg_split(self::PATTERN_SPLIT_AT_RESOURCE_URIS, $node->getText(), -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
+        $textParts = preg_split(self::PATTERN_SPLIT_AT_RESOURCE_URIS, $node->getText(), -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE) ?: [];
         $node = new RootNode();
         foreach ($textParts as $part) {
             $matches = [];
@@ -109,7 +109,7 @@ public function process(NodeInterface $node, $interceptorPosition, ParsingState
                 if ($this->defaultPackageKey !== null) {
                     $arguments['package'] = new TextNode($this->defaultPackageKey);
                 }
-                if (isset($matches['Package']) && FlowPackageKey::isPackageKeyValid($matches['Package'])) {
+                if (FlowPackageKey::isPackageKeyValid($matches['Package'])) {
                     $arguments['package'] = new TextNode($matches['Package']);
                 }
 
@@ -127,7 +127,7 @@ public function process(NodeInterface $node, $interceptorPosition, ParsingState
     /**
      * This interceptor wants to hook into text nodes.
      *
-     * @return array Array of INTERCEPT_* constants
+     * @return array<int,int> Array of INTERCEPT_* constants
      */
     public function getInterceptionPoints()
     {
diff --git a/Neos.FluidAdaptor/Classes/Core/Parser/SyntaxTree/Expression/LegacyNamespaceExpressionNode.php b/Neos.FluidAdaptor/Classes/Core/Parser/SyntaxTree/Expression/LegacyNamespaceExpressionNode.php
index 1af2886355..cd63f4f625 100644
--- a/Neos.FluidAdaptor/Classes/Core/Parser/SyntaxTree/Expression/LegacyNamespaceExpressionNode.php
+++ b/Neos.FluidAdaptor/Classes/Core/Parser/SyntaxTree/Expression/LegacyNamespaceExpressionNode.php
@@ -24,14 +24,14 @@ class LegacyNamespaceExpressionNode extends AbstractExpressionNode implements Ex
      * Pattern which detects namespace declarations made inline.
      * syntax, e.g. {namespace neos=TYPO3\Neos\ViewHelpers}.
      */
-    public static $detectionExpression = '/{namespace\\s*([a-z0-9]+)\\s*=\\s*([a-z0-9_\\\\]+)\\s*}/i';
+    public static string $detectionExpression = '/{namespace\\s*([a-z0-9]+)\\s*=\\s*([a-z0-9_\\\\]+)\\s*}/i';
 
     /**
      * Evaluates the expression stored in this node, in the context of $renderingcontext.
      *
      * @param RenderingContextInterface $renderingContext
      * @param string $expression
-     * @param array $matches
+     * @param array<int,mixed> $matches
      * @return mixed
      */
     public static function evaluateExpression(RenderingContextInterface $renderingContext, $expression, array $matches)
diff --git a/Neos.FluidAdaptor/Classes/Core/Parser/SyntaxTree/ResourceUriNode.php b/Neos.FluidAdaptor/Classes/Core/Parser/SyntaxTree/ResourceUriNode.php
index db44103330..81301ef0d4 100644
--- a/Neos.FluidAdaptor/Classes/Core/Parser/SyntaxTree/ResourceUriNode.php
+++ b/Neos.FluidAdaptor/Classes/Core/Parser/SyntaxTree/ResourceUriNode.php
@@ -35,18 +35,17 @@ class ResourceUriNode extends ViewHelperNode
     protected $viewHelperResolver;
 
     /**
-     * @var string
+     * @var class-string<ResourceViewHelper>
      */
     protected $viewHelperClassName = ResourceViewHelper::class;
 
     /**
      * @param ViewHelperResolver $viewHelperResolver
      */
-    public function injectViewHelperResolver(ViewHelperResolver $viewHelperResolver)
+    public function injectViewHelperResolver(ViewHelperResolver $viewHelperResolver): void
     {
         $this->viewHelperResolver = $viewHelperResolver;
         $this->uninitializedViewHelper = $this->viewHelperResolver->createViewHelperInstanceFromClassName($this->viewHelperClassName);
-        /** @phpstan-ignore-next-line we use internal api */
         $this->uninitializedViewHelper->setViewHelperNode($this);
         $this->argumentDefinitions = $this->viewHelperResolver->getArgumentDefinitionsForViewHelper($this->uninitializedViewHelper);
     }
diff --git a/Neos.FluidAdaptor/Classes/Core/Parser/TemplateParser.php b/Neos.FluidAdaptor/Classes/Core/Parser/TemplateParser.php
index 1ad1054885..db67139b41 100644
--- a/Neos.FluidAdaptor/Classes/Core/Parser/TemplateParser.php
+++ b/Neos.FluidAdaptor/Classes/Core/Parser/TemplateParser.php
@@ -17,7 +17,7 @@ public function isEscapingEnabled()
     /**
      * @param boolean $escapingEnabled
      */
-    public function setEscapingEnabled($escapingEnabled)
+    public function setEscapingEnabled($escapingEnabled): void
     {
         $this->escapingEnabled = $escapingEnabled;
     }
diff --git a/Neos.FluidAdaptor/Classes/Core/Parser/TemplateProcessor/EscapingFlagProcessor.php b/Neos.FluidAdaptor/Classes/Core/Parser/TemplateProcessor/EscapingFlagProcessor.php
index fbdc9a72a1..1b61da951e 100644
--- a/Neos.FluidAdaptor/Classes/Core/Parser/TemplateProcessor/EscapingFlagProcessor.php
+++ b/Neos.FluidAdaptor/Classes/Core/Parser/TemplateProcessor/EscapingFlagProcessor.php
@@ -25,12 +25,12 @@ class EscapingFlagProcessor implements TemplateProcessorInterface
      */
     protected $renderingContext;
 
-    public static $SCAN_PATTERN_ESCAPINGMODIFIER = '/{escapingEnabled\s*=\s*(?P<enabled>true|false)\s*}/i';
+    public static string $SCAN_PATTERN_ESCAPINGMODIFIER = '/{escapingEnabled\s*=\s*(?P<enabled>true|false)\s*}/i';
 
     /**
      * @param RenderingContextInterface $renderingContext
      */
-    public function setRenderingContext(RenderingContextInterface $renderingContext)
+    public function setRenderingContext(RenderingContextInterface $renderingContext): void
     {
         $this->renderingContext = $renderingContext;
     }
@@ -56,7 +56,7 @@ public function preProcessSource($templateSource)
         if (strtolower($matches[0]['enabled']) === 'false') {
             $this->renderingContext->getTemplateParser()->setEscapingEnabled(false);
         }
-        $templateSource = preg_replace(self::$SCAN_PATTERN_ESCAPINGMODIFIER, '', $templateSource);
+        $templateSource = preg_replace(self::$SCAN_PATTERN_ESCAPINGMODIFIER, '', $templateSource) ?: '';
 
         return $templateSource;
     }
diff --git a/Neos.FluidAdaptor/Classes/Core/Parser/TemplateProcessor/NamespaceDetectionTemplateProcessor.php b/Neos.FluidAdaptor/Classes/Core/Parser/TemplateProcessor/NamespaceDetectionTemplateProcessor.php
index b6c18f2664..3c813c0c01 100644
--- a/Neos.FluidAdaptor/Classes/Core/Parser/TemplateProcessor/NamespaceDetectionTemplateProcessor.php
+++ b/Neos.FluidAdaptor/Classes/Core/Parser/TemplateProcessor/NamespaceDetectionTemplateProcessor.php
@@ -29,7 +29,7 @@ class NamespaceDetectionTemplateProcessor extends FluidNamespaceDetectionTemplat
     /**
      * Extension of the default pattern for dynamic tags including namespaces with uppercase letters.
      */
-    public static $EXTENDED_SPLIT_PATTERN_TEMPLATE_DYNAMICTAGS = '/
+    public static string $EXTENDED_SPLIT_PATTERN_TEMPLATE_DYNAMICTAGS = '/
 		(
 			(?: <\/?                                      # Start dynamic tags
 					(?:(?:[a-zA-Z0-9\\.]*):[a-zA-Z0-9\\.]+)  # A tag consists of the namespace prefix and word characters
@@ -75,7 +75,7 @@ public function preProcessSource($templateSource)
      */
     public function protectCDataSectionsFromParser(string $templateSource)
     {
-        $parts = preg_split('/(\<\!\[CDATA\[|\]\]\>)/', $templateSource, -1, PREG_SPLIT_DELIM_CAPTURE);
+        $parts = preg_split('/(\<\!\[CDATA\[|\]\]\>)/', $templateSource, -1, PREG_SPLIT_DELIM_CAPTURE) ?: [];
         $balance = 0;
         $content = '';
         $resultingParts = [];
@@ -127,7 +127,7 @@ public function protectCDataSectionsFromParser(string $templateSource)
     public function throwExceptionsForUnhandledNamespaces(string $templateSource): void
     {
         $viewHelperResolver = $this->renderingContext->getViewHelperResolver();
-        $splitTemplate = preg_split(static::$EXTENDED_SPLIT_PATTERN_TEMPLATE_DYNAMICTAGS, $templateSource, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
+        $splitTemplate = preg_split(static::$EXTENDED_SPLIT_PATTERN_TEMPLATE_DYNAMICTAGS, $templateSource, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY) ?: [];
         foreach ($splitTemplate as $templateElement) {
             if (preg_match(Patterns::$SCAN_PATTERN_TEMPLATE_VIEWHELPERTAG, $templateElement, $matchedVariables) > 0) {
                 if (!$viewHelperResolver->isNamespaceValidOrIgnored($matchedVariables['NamespaceIdentifier'])) {
@@ -148,11 +148,9 @@ public function throwExceptionsForUnhandledNamespaces(string $templateSource): v
             foreach ($sections as $section) {
                 if (preg_match(Patterns::$SCAN_PATTERN_SHORTHANDSYNTAX_OBJECTACCESSORS, $section, $matchedVariables) > 0) {
                     preg_match_all(Patterns::$SPLIT_PATTERN_SHORTHANDSYNTAX_VIEWHELPER, $section, $shorthandViewHelpers, PREG_SET_ORDER);
-                    if (is_array($shorthandViewHelpers) === true) {
-                        foreach ($shorthandViewHelpers as $shorthandViewHelper) {
-                            if (!$viewHelperResolver->isNamespaceValidOrIgnored($shorthandViewHelper['NamespaceIdentifier'])) {
-                                throw new UnknownNamespaceException('Unknown Namespace: ' . $shorthandViewHelper['NamespaceIdentifier']);
-                            }
+                    foreach ($shorthandViewHelpers as $shorthandViewHelper) {
+                        if (!$viewHelperResolver->isNamespaceValidOrIgnored($shorthandViewHelper['NamespaceIdentifier'])) {
+                            throw new UnknownNamespaceException('Unknown Namespace: ' . $shorthandViewHelper['NamespaceIdentifier']);
                         }
                     }
                 }
diff --git a/Neos.FluidAdaptor/Classes/Core/Rendering/RenderingContext.php b/Neos.FluidAdaptor/Classes/Core/Rendering/RenderingContext.php
index 3c68fb552b..1fb6c223f5 100644
--- a/Neos.FluidAdaptor/Classes/Core/Rendering/RenderingContext.php
+++ b/Neos.FluidAdaptor/Classes/Core/Rendering/RenderingContext.php
@@ -25,6 +25,7 @@
 use Neos\FluidAdaptor\Core\ViewHelper\ViewHelperResolver;
 use Neos\FluidAdaptor\View\TemplatePaths;
 use TYPO3Fluid\Fluid\Core\Parser\Configuration;
+use TYPO3Fluid\Fluid\Core\Parser\SyntaxTree\Expression\AbstractExpressionNode;
 use TYPO3Fluid\Fluid\Core\Parser\SyntaxTree\Expression\CastingExpressionNode;
 use TYPO3Fluid\Fluid\Core\Parser\SyntaxTree\Expression\MathExpressionNode;
 use TYPO3Fluid\Fluid\Core\Parser\SyntaxTree\Expression\TernaryExpressionNode;
@@ -42,7 +43,7 @@ class RenderingContext extends FluidRenderingContext implements FlowAwareRenderi
      * which will be consulted when an expression does not match
      * any built-in parser expression types.
      *
-     * @var array
+     * @var array<class-string<AbstractExpressionNode>>
      */
     protected $expressionNodeTypes = [
         LegacyNamespaceExpressionNode::class,
@@ -81,7 +82,7 @@ class RenderingContext extends FluidRenderingContext implements FlowAwareRenderi
     /**
      * RenderingContext constructor.
      *
-     * @param array $options
+     * @param array<string,mixed> $options
      */
     public function __construct(array $options = [])
     {
@@ -100,7 +101,7 @@ public function __construct(array $options = [])
     /**
      * @param ObjectManagerInterface $objectManager
      */
-    public function injectObjectManager(ObjectManagerInterface $objectManager)
+    public function injectObjectManager(ObjectManagerInterface $objectManager): void
     {
         $this->objectManager = $objectManager;
     }
@@ -116,11 +117,11 @@ public function getControllerContext()
     /**
      * @param ControllerContext $controllerContext
      */
-    public function setControllerContext($controllerContext)
+    public function setControllerContext($controllerContext): void
     {
         $this->controllerContext = $controllerContext;
         $request = $controllerContext->getRequest();
-        if (!$this->templatePaths instanceof TemplatePaths || !$request instanceof ActionRequest) {
+        if (!$this->templatePaths instanceof TemplatePaths) {
             return;
         }
 
diff --git a/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractConditionViewHelper.php b/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractConditionViewHelper.php
index 052ef09e98..60c8b848f9 100644
--- a/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractConditionViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractConditionViewHelper.php
@@ -46,7 +46,7 @@ abstract class AbstractConditionViewHelper extends AbstractViewHelper
     /**
      * Initializes the "then" and "else" arguments
      */
-    public function initializeArguments()
+    public function initializeArguments(): void
     {
         $this->registerArgument('then', 'mixed', 'Value to be returned if the condition if met.', false);
         $this->registerArgument('else', 'mixed', 'Value to be returned if the condition if not met.', false);
@@ -66,18 +66,19 @@ public function initializeArguments()
      * subclasses that will be using this base class in the future. Let this
      * be a warning if someone considers changing this method signature!
      *
-     * @param array|NULL $arguments
+     * @param array<mixed>|NULL $arguments
      * @param RenderingContextInterface $renderingContext
      * @return boolean
      * @api
      */
     protected static function evaluateCondition($arguments, RenderingContextInterface $renderingContext)
     {
-        return (boolean)$arguments['condition'];
+        // fallback value derived from registerArgument default value
+        return (boolean)($arguments['condition'] ?? false);
     }
 
     /**
-     * @param array $arguments
+     * @param array<string,mixed> $arguments
      * @param \Closure $renderChildrenClosure
      * @param RenderingContextInterface $renderingContext
      * @return mixed
@@ -103,8 +104,8 @@ public static function renderStatic(array $arguments, \Closure $renderChildrenCl
     }
 
     /**
-     * @param array $closures
-     * @param array $conditionClosures
+     * @param array<mixed> $closures
+     * @param array<mixed> $conditionClosures
      * @param RenderingContextInterface $renderingContext
      * @return string
      */
@@ -236,7 +237,7 @@ public function compile($argumentsName, $closureName, &$initializationPhpCode, V
 
     /**
      * @param boolean $isConditionFullfilled
-     * @param array $arguments
+     * @param array<string,mixed> $arguments
      * @param RenderingContextInterface $renderingContext
      * @return mixed
      */
diff --git a/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractLocaleAwareViewHelper.php b/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractLocaleAwareViewHelper.php
index 5f33d1e651..436817dfea 100644
--- a/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractLocaleAwareViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractLocaleAwareViewHelper.php
@@ -39,7 +39,7 @@ public function __construct()
     /**
      * @param I18n\Service $localizationService
      */
-    public function injectLocalizationService(I18n\Service $localizationService)
+    public function injectLocalizationService(I18n\Service $localizationService): void
     {
         $this->localizationService = $localizationService;
     }
diff --git a/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractTagBasedViewHelper.php b/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractTagBasedViewHelper.php
index d4743808a6..2ce96b048d 100644
--- a/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractTagBasedViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractTagBasedViewHelper.php
@@ -32,7 +32,7 @@ abstract class AbstractTagBasedViewHelper extends AbstractViewHelper
     /**
      * Names of all registered tag attributes
      *
-     * @var array
+     * @var array<mixed>
      */
     private static $tagAttributes = [];
 
@@ -156,7 +156,7 @@ protected function registerUniversalTagAttributes()
      * which in the default implementation will throw an error
      * about "undeclared argument used".
      *
-     * @param array $arguments
+     * @param array<string,string|\Traversable<mixed>|array<mixed>|null> $arguments
      * @return void
      */
     public function handleAdditionalArguments(array $arguments)
diff --git a/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractViewHelper.php b/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractViewHelper.php
index 6731a63562..e80a9b38de 100644
--- a/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/Core/ViewHelper/AbstractViewHelper.php
@@ -59,9 +59,7 @@ public function setRenderingContext(RenderingContextInterface $renderingContext)
         $this->renderingContext = $renderingContext;
         $this->templateVariableContainer = $renderingContext->getVariableProvider();
         $this->viewHelperVariableContainer = $renderingContext->getViewHelperVariableContainer();
-        if ($renderingContext instanceof FlowAwareRenderingContextInterface) {
-            $this->controllerContext = $renderingContext->getControllerContext();
-        }
+        $this->controllerContext = $renderingContext->getControllerContext();
     }
 
     /**
diff --git a/Neos.FluidAdaptor/Classes/Core/ViewHelper/ViewHelperResolver.php b/Neos.FluidAdaptor/Classes/Core/ViewHelper/ViewHelperResolver.php
index 8351bfa4f1..9282263018 100644
--- a/Neos.FluidAdaptor/Classes/Core/ViewHelper/ViewHelperResolver.php
+++ b/Neos.FluidAdaptor/Classes/Core/ViewHelper/ViewHelperResolver.php
@@ -15,6 +15,7 @@
 use Neos\Flow\ObjectManagement\ObjectManagerInterface;
 use Neos\Flow\Package\Package;
 use Neos\Flow\Package\PackageManager;
+use TYPO3Fluid\Fluid\Core\ViewHelper\ViewHelperInterface;
 
 /**
  * Class ViewHelperResolver
@@ -49,17 +50,17 @@ class ViewHelperResolver extends \TYPO3Fluid\Fluid\Core\ViewHelper\ViewHelperRes
      * will look for classes in both namespaces starting
      * from the bottom.
      *
-     * @var array
+     * @var array<mixed>
      */
     protected $namespaces = [];
 
     /**
      * @Flow\InjectConfiguration(path="namespaces")
-     * @var array
+     * @var array<mixed>
      */
     protected $namespacesFromConfiguration;
 
-    public function initializeObject($reason)
+    public function initializeObject(int $reason): void
     {
         if ($reason === ObjectManagerInterface::INITIALIZATIONCAUSE_RECREATED) {
             return;
@@ -83,8 +84,9 @@ public function initializeObject($reason)
     }
 
     /**
-     * @param string $viewHelperClassName
-     * @return \TYPO3Fluid\Fluid\Core\ViewHelper\ViewHelperInterface
+     * @template T of ViewHelperInterface
+     * @param class-string<T> $viewHelperClassName
+     * @return T
      */
     public function createViewHelperInstanceFromClassName($viewHelperClassName)
     {
@@ -125,7 +127,7 @@ public function createViewHelperInstanceFromClassName($viewHelperClassName)
      * when you use this method you should always include the "f" namespace.
      *
      * @param string $identifier
-     * @param string|array $phpNamespace
+     * @param string|array<string>|null $phpNamespace
      * @return void
      */
     public function addNamespace($identifier, $phpNamespace)
@@ -149,7 +151,7 @@ public function addNamespace($identifier, $phpNamespace)
      * @param string $identifier
      * @param string $phpNamespace
      */
-    protected function addNamespaceInternal($identifier, $phpNamespace)
+    protected function addNamespaceInternal($identifier, $phpNamespace): void
     {
         if (!isset($this->namespaces[$identifier])) {
             $this->namespaces[$identifier] = [];
diff --git a/Neos.FluidAdaptor/Classes/Core/Widget/AbstractWidgetController.php b/Neos.FluidAdaptor/Classes/Core/Widget/AbstractWidgetController.php
index c7b38b4a80..4c07eab1e2 100644
--- a/Neos.FluidAdaptor/Classes/Core/Widget/AbstractWidgetController.php
+++ b/Neos.FluidAdaptor/Classes/Core/Widget/AbstractWidgetController.php
@@ -36,7 +36,7 @@ abstract class AbstractWidgetController extends ActionController
     /**
      * Configuration for this widget.
      *
-     * @var array
+     * @var array<mixed>
      * @api
      */
     protected $widgetConfiguration;
@@ -60,7 +60,6 @@ abstract class AbstractWidgetController extends ActionController
      */
     public function processRequest(ActionRequest $request): ResponseInterface
     {
-        /** @var WidgetContext $widgetContext */
         $widgetContext = $request->getInternalArgument('__widgetContext');
         if (!$widgetContext instanceof WidgetContext) {
             throw new WidgetContextNotFoundException('The widget context could not be found in the request.', 1307450180);
diff --git a/Neos.FluidAdaptor/Classes/Core/Widget/AbstractWidgetViewHelper.php b/Neos.FluidAdaptor/Classes/Core/Widget/AbstractWidgetViewHelper.php
index e390a32db6..db341c1186 100644
--- a/Neos.FluidAdaptor/Classes/Core/Widget/AbstractWidgetViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/Core/Widget/AbstractWidgetViewHelper.php
@@ -20,6 +20,7 @@
 use Neos\FluidAdaptor\Core\ViewHelper\AbstractViewHelper;
 use Neos\FluidAdaptor\Core\ViewHelper\Facets\ChildNodeAccessInterface;
 use TYPO3Fluid\Fluid\Core\Compiler\TemplateCompiler;
+use TYPO3Fluid\Fluid\Core\Parser\SyntaxTree\NodeInterface;
 use TYPO3Fluid\Fluid\Core\Parser\SyntaxTree\RootNode;
 use TYPO3Fluid\Fluid\Core\Parser\SyntaxTree\ViewHelperNode;
 
@@ -38,7 +39,7 @@ abstract class AbstractWidgetViewHelper extends AbstractViewHelper implements Ch
      * This needs to be filled by the individual subclass using
      * property injection.
      *
-     * @var AbstractWidgetController
+     * @var AbstractWidgetController|DependencyProxy
      * @api
      */
     protected $controller;
@@ -150,7 +151,7 @@ private function initializeWidgetContext()
      * Stores the syntax tree child nodes in the Widget Context, so they can be
      * rendered with <f:widget.renderChildren> lateron.
      *
-     * @param array $childNodes The SyntaxTree Child nodes of this ViewHelper.
+     * @param array<NodeInterface> $childNodes The SyntaxTree Child nodes of this ViewHelper.
      * @return void
      */
     public function setChildNodes(array $childNodes)
@@ -166,7 +167,7 @@ public function setChildNodes(array $childNodes)
     /**
      * Generate the configuration for this widget. Override to adjust.
      *
-     * @return array
+     * @return array<mixed>
      * @api
      */
     protected function getWidgetConfiguration()
@@ -179,7 +180,7 @@ protected function getWidgetConfiguration()
      *
      * By default, returns getWidgetConfiguration(). Should become API later.
      *
-     * @return array
+     * @return array<mixed>
      */
     protected function getAjaxWidgetConfiguration()
     {
@@ -191,7 +192,7 @@ protected function getAjaxWidgetConfiguration()
      *
      * By default, returns getWidgetConfiguration(). Should become API later.
      *
-     * @return array
+     * @return array<mixed>
      */
     protected function getNonAjaxWidgetConfiguration()
     {
@@ -231,6 +232,9 @@ protected function initiateSubRequest()
             }
             $subRequest->setControllerObjectName($this->widgetContext->getControllerObjectName());
             try {
+                if (!($this->controller instanceof AbstractWidgetController)) {
+                    throw new Exception\MissingControllerException('initiateSubRequest() can not be called if there is no controller inside $this->controller. Make sure to add the @Neos\Flow\Annotations\Inject annotation in your widget class.', 1284401632);
+                }
                 $subResponse = $this->controller->processRequest($subRequest);
 
                 // We need to make sure to not merge content up into the parent ActionResponse because that _could_ break the parent response.
diff --git a/Neos.FluidAdaptor/Classes/Core/Widget/AjaxWidgetContextHolder.php b/Neos.FluidAdaptor/Classes/Core/Widget/AjaxWidgetContextHolder.php
index f78a163c2f..81a7077866 100644
--- a/Neos.FluidAdaptor/Classes/Core/Widget/AjaxWidgetContextHolder.php
+++ b/Neos.FluidAdaptor/Classes/Core/Widget/AjaxWidgetContextHolder.php
@@ -30,7 +30,7 @@ class AjaxWidgetContextHolder
      * An array $ajaxWidgetIdentifier => $widgetContext
      * which stores the widget context.
      *
-     * @var array
+     * @var array<string,WidgetContext>
      */
     protected $widgetContexts = [];
 
diff --git a/Neos.FluidAdaptor/Classes/Core/Widget/WidgetContext.php b/Neos.FluidAdaptor/Classes/Core/Widget/WidgetContext.php
index de1beed414..fb679f500f 100644
--- a/Neos.FluidAdaptor/Classes/Core/Widget/WidgetContext.php
+++ b/Neos.FluidAdaptor/Classes/Core/Widget/WidgetContext.php
@@ -48,7 +48,7 @@ class WidgetContext
      * controller as $this->widgetConfiguration, if being inside an AJAX
      * request
      *
-     * @var array
+     * @var array<mixed>
      */
     protected $ajaxWidgetConfiguration;
 
@@ -57,7 +57,7 @@ class WidgetContext
      * controller as $this->widgetConfiguration, if being inside a non-AJAX
      * request
      *
-     * @var array
+     * @var array<mixed>
      */
     protected $nonAjaxWidgetConfiguration;
     /**
@@ -71,7 +71,7 @@ class WidgetContext
      * The child nodes of the Widget ViewHelper.
      * Only available inside non-AJAX requests.
      *
-     * @var RootNode
+     * @var ?RootNode
      * @Flow\Transient
      */
     protected $viewHelperChildNodes;
@@ -80,7 +80,7 @@ class WidgetContext
      * The rendering context of the ViewHelperChildNodes.
      * Only available inside non-AJAX requests.
      *
-     * @var RenderingContextInterface
+     * @var ?RenderingContextInterface
      * @Flow\Transient
      */
     protected $viewHelperChildNodeRenderingContext;
@@ -120,7 +120,7 @@ public function setAjaxWidgetIdentifier($ajaxWidgetIdentifier)
     }
 
     /**
-     * @return array
+     * @return array<mixed>
      */
     public function getWidgetConfiguration()
     {
@@ -132,7 +132,7 @@ public function getWidgetConfiguration()
     }
 
     /**
-     * @param array $ajaxWidgetConfiguration
+     * @param array<mixed> $ajaxWidgetConfiguration
      * @return void
      */
     public function setAjaxWidgetConfiguration(array $ajaxWidgetConfiguration)
@@ -141,7 +141,7 @@ public function setAjaxWidgetConfiguration(array $ajaxWidgetConfiguration)
     }
 
     /**
-     * @param array $nonAjaxWidgetConfiguration
+     * @param array<mixed> $nonAjaxWidgetConfiguration
      * @return void
      */
     public function setNonAjaxWidgetConfiguration(array $nonAjaxWidgetConfiguration)
@@ -178,17 +178,14 @@ public function setViewHelperChildNodes(RootNode $viewHelperChildNodes, Renderin
     }
 
     /**
-     * @return RootNode
+     * @return ?RootNode
      */
     public function getViewHelperChildNodes()
     {
         return $this->viewHelperChildNodes;
     }
 
-    /**
-     * @return RenderingContextInterface
-     */
-    public function getViewHelperChildNodeRenderingContext()
+    public function getViewHelperChildNodeRenderingContext(): ?RenderingContextInterface
     {
         return $this->viewHelperChildNodeRenderingContext;
     }
diff --git a/Neos.FluidAdaptor/Classes/Service/AbstractGenerator.php b/Neos.FluidAdaptor/Classes/Service/AbstractGenerator.php
index 0b37087aab..6001780143 100644
--- a/Neos.FluidAdaptor/Classes/Service/AbstractGenerator.php
+++ b/Neos.FluidAdaptor/Classes/Service/AbstractGenerator.php
@@ -54,7 +54,7 @@ public function __construct()
      * Get all class names inside this namespace and return them as array.
      *
      * @param string $namespace
-     * @return array Array of all class names inside a given namespace.
+     * @return array<int,class-string<AbstractViewHelper>> Array of all class names inside a given namespace.
      */
     protected function getClassNamesInNamespace($namespace)
     {
@@ -101,7 +101,7 @@ protected function getTagNameForClass($className, $namespace)
      * @param \SimpleXMLElement $parentXmlNode Parent XML Node to add the child to
      * @param string $childNodeName Name of the child node
      * @param string $childNodeValue Value of the child node. Will be placed inside CDATA.
-     * @return \SimpleXMLElement the new element
+     * @return ?\SimpleXMLElement the new element
      */
     protected function addChildWithCData(\SimpleXMLElement $parentXmlNode, $childNodeName, $childNodeValue)
     {
@@ -110,8 +110,12 @@ protected function addChildWithCData(\SimpleXMLElement $parentXmlNode, $childNod
 
         $childNode = $domDocument->appendChild($domDocument->createElement($childNodeName));
         $childNode->appendChild($domDocument->createCDATASection($childNodeValue));
-        $childNodeTarget = $parentDomNode->ownerDocument->importNode($childNode, true);
-        $parentDomNode->appendChild($childNodeTarget);
-        return simplexml_import_dom($childNodeTarget);
+        $childNodeTarget = $parentDomNode->ownerDocument?->importNode($childNode, true);
+        if ($childNodeTarget instanceof \DOMNode) {
+            $parentDomNode->appendChild($childNodeTarget);
+            return simplexml_import_dom($childNodeTarget);
+        }
+
+        return null;
     }
 }
diff --git a/Neos.FluidAdaptor/Classes/Service/XsdGenerator.php b/Neos.FluidAdaptor/Classes/Service/XsdGenerator.php
index c67220d2e9..be4fda8617 100644
--- a/Neos.FluidAdaptor/Classes/Service/XsdGenerator.php
+++ b/Neos.FluidAdaptor/Classes/Service/XsdGenerator.php
@@ -54,7 +54,11 @@ public function generateXsd($viewHelperNamespace, $xsdNamespace)
             $this->generateXmlForClassName($className, $viewHelperNamespace, $xmlRootNode);
         }
 
-        return $xmlRootNode->asXML();
+        $result = $xmlRootNode->asXML();
+
+        return is_string($result)
+            ? $result
+            : throw new \Exception('Failed to generate xsd', 1743851104);
     }
 
     /**
@@ -75,15 +79,22 @@ protected function generateXmlForClassName($className, $viewHelperNamespace, \Si
         $tagName = $this->getTagNameForClass($className, $viewHelperNamespace);
 
         $xsdElement = $xmlRootNode->addChild('xsd:element');
+        /** @phpstan-ignore argument.type (offsetSet accepts mixed) */
         $xsdElement->offsetSet('name', $tagName);
-        $this->docCommentParser->parseDocComment($reflectionClass->getDocComment());
+        $docComment = $reflectionClass->getDocComment();
+        if ($docComment !== false) {
+            $this->docCommentParser->parseDocComment($docComment);
+        }
         $this->addDocumentation($this->docCommentParser->getDescription(), $xsdElement);
 
         $xsdComplexType = $xsdElement->addChild('xsd:complexType');
+        /** @phpstan-ignore argument.type (offsetSet accepts mixed) */
         $xsdComplexType->offsetSet('mixed', 'true');
         $xsdSequence = $xsdComplexType->addChild('xsd:sequence');
         $xsdAny = $xsdSequence->addChild('xsd:any');
+        /** @phpstan-ignore argument.type (offsetSet accepts mixed) */
         $xsdAny->offsetSet('minOccurs', '0');
+        /** @phpstan-ignore argument.type (offsetSet accepts mixed) */
         $xsdAny->offsetSet('maxOccurs', 'unbounded');
 
         $this->addAttributes($className, $xsdComplexType);
@@ -106,10 +117,13 @@ protected function addAttributes($className, \SimpleXMLElement $xsdElement)
         foreach ($argumentDefinitions as $argumentDefinition) {
             /** @var \SimpleXMLElement $xsdAttribute */
             $xsdAttribute = $xsdElement->addChild('xsd:attribute');
+            /** @phpstan-ignore argument.type (offsetSet accepts mixed) */
             $xsdAttribute->offsetSet('type', 'xsd:string');
+            /** @phpstan-ignore argument.type (offsetSet accepts mixed) */
             $xsdAttribute->offsetSet('name', $argumentDefinition->getName());
             $this->addDocumentation($argumentDefinition->getDescription(), $xsdAttribute);
             if ($argumentDefinition->isRequired()) {
+                /** @phpstan-ignore argument.type (offsetSet accepts mixed) */
                 $xsdAttribute->offsetSet('use', 'required');
             }
         }
diff --git a/Neos.FluidAdaptor/Classes/View/AbstractTemplateView.php b/Neos.FluidAdaptor/Classes/View/AbstractTemplateView.php
index 37a64bfa17..162312c818 100644
--- a/Neos.FluidAdaptor/Classes/View/AbstractTemplateView.php
+++ b/Neos.FluidAdaptor/Classes/View/AbstractTemplateView.php
@@ -36,7 +36,7 @@ abstract class AbstractTemplateView extends \TYPO3Fluid\Fluid\View\AbstractTempl
      *         ...
      *     )
      *
-     * @var array
+     * @var array<string,mixed>
      */
     protected $supportedOptions = [
         'templateRootPathPattern' => [
@@ -101,7 +101,7 @@ abstract class AbstractTemplateView extends \TYPO3Fluid\Fluid\View\AbstractTempl
      *
      * @see $supportedOptions
      *
-     * @var array
+     * @var array<string,mixed>
      */
     protected $options = [];
 
@@ -124,6 +124,9 @@ public function assign($key, $value): self
         return parent::assign($key, $value);
     }
 
+    /**
+     * @param array<string,mixed> $values
+     */
     public function assignMultiple(array $values): self
     {
         // layer to fix incompatibility error with typo3 fluid interface
@@ -133,7 +136,7 @@ public function assignMultiple(array $values): self
     /**
      * Factory method to create an instance with given options.
      *
-     * @param array $options
+     * @param array<string,mixed> $options
      * @return static
      */
     public static function createWithOptions(array $options): self
@@ -144,7 +147,7 @@ public static function createWithOptions(array $options): self
     /**
      * Set default options based on the supportedOptions provided
      *
-     * @param array $options
+     * @param array<string,mixed>|null $options
      * @throws Exception
      */
     public function __construct(?array $options = null)
@@ -184,14 +187,9 @@ public function setControllerContext(ControllerContext $controllerContext)
             $renderingContext->setControllerContext($controllerContext);
         }
 
-
         $paths = $this->getTemplatePaths();
         $request = $controllerContext->getRequest();
 
-        if (!$request instanceof ActionRequest) {
-            return;
-        }
-
         $paths->setFormat($request->getFormat());
 
         if ($paths->getTemplateRootPaths() === [] && $paths->getLayoutRootPaths() === [] && $paths->getPartialRootPaths() === []) {
@@ -205,7 +203,7 @@ public function setControllerContext(ControllerContext $controllerContext)
      * Renders a given section.
      *
      * @param string $sectionName Name of section to render
-     * @param array $variables The variables to use
+     * @param array<string,mixed> $variables The variables to use
      * @param boolean $ignoreUnknown Ignore an unknown section and just return an empty string
      * @return string rendered template for the section
      * @throws \Neos\FluidAdaptor\View\Exception\InvalidSectionException
@@ -217,13 +215,14 @@ public function renderSection($sectionName, array $variables = [], $ignoreUnknow
             $variables = $this->getRenderingContext()->getVariableProvider()->getAll();
         }
 
+        /** @phpstan-ignore argument.type (we assume Fluid actually supports \ArrayAccess here, too) */
         return parent::renderSection($sectionName, $variables, $ignoreUnknown);
     }
 
     /**
      * Validate options given to this view.
      *
-     * @param array $options
+     * @param array<string,mixed> $options
      * @return void
      * @throws Exception
      */
@@ -250,10 +249,10 @@ function ($supportedOptionData, $supportedOptionName, $options) {
      * Merges the given options with the default values
      * and sets the resulting options in this object.
      *
-     * @param array $options
+     * @param array<string,mixed> $options
      * @return void
      */
-    protected function setOptions(array $options)
+    protected function setOptions(array $options): void
     {
         $this->options = array_merge(
             array_map(
diff --git a/Neos.FluidAdaptor/Classes/View/StandaloneView.php b/Neos.FluidAdaptor/Classes/View/StandaloneView.php
index 6fdb79413a..d4a3cbfc6f 100644
--- a/Neos.FluidAdaptor/Classes/View/StandaloneView.php
+++ b/Neos.FluidAdaptor/Classes/View/StandaloneView.php
@@ -51,7 +51,7 @@ class StandaloneView extends AbstractTemplateView
     protected $environment;
 
     /**
-     * @var ActionRequest
+     * @var ?ActionRequest
      */
     protected $request;
 
@@ -64,7 +64,7 @@ class StandaloneView extends AbstractTemplateView
     /**
      * Factory method to create an instance with given options.
      *
-     * @param array $options
+     * @param array<string,mixed> $options
      * @return static
      */
     public static function createWithOptions(array $options): self
@@ -75,11 +75,12 @@ public static function createWithOptions(array $options): self
     /**
      * Constructor
      *
-     * @param ActionRequest $request The current action request. If none is specified it will be created from the environment.
-     * @param array $options
+     * @param ?ActionRequest $request The current action request. If none is specified it will be created from the environment.
+     * @param array<string,mixed>|null $options
      * @throws \Neos\FluidAdaptor\Exception
+     * @phpstan-ignore method.childParameterType (parameters are differently ordered and thus cannot match)
      */
-    public function __construct(?ActionRequest $request = null, array $options = [])
+    public function __construct(?ActionRequest $request = null, ?array $options = [])
     {
         $this->request = $request;
         parent::__construct($options);
@@ -116,7 +117,7 @@ public function initializeObject()
     /**
      * @param string $templateName
      */
-    public function setTemplate($templateName)
+    public function setTemplate($templateName): void
     {
         $this->baseRenderingContext->setControllerAction($templateName);
     }
@@ -130,6 +131,9 @@ public function setTemplate($templateName)
      */
     public function setFormat($format)
     {
+        if (!$this->request) {
+            throw new \Exception('Cannot set format without a request', 1743856310);
+        }
         $this->request->setFormat($format);
         $this->baseRenderingContext->getTemplatePaths()->setFormat($format);
     }
@@ -137,18 +141,18 @@ public function setFormat($format)
     /**
      * Returns the format of the current request (defaults is "html")
      *
-     * @return string $format
+     * @return ?string $format
      * @api
      */
     public function getFormat()
     {
-        return $this->request->getFormat();
+        return $this->request?->getFormat();
     }
 
     /**
      * Returns the current request object
      *
-     * @return ActionRequest
+     * @return ?ActionRequest
      */
     public function getRequest()
     {
@@ -177,12 +181,20 @@ public function setTemplatePathAndFilename($templatePathAndFilename)
     /**
      * Returns the absolute path to a Fluid template file if it was specified with setTemplatePathAndFilename() before
      *
-     * @return string Fluid template path
+     * @return ?string Fluid template path
      * @api
      */
     public function getTemplatePathAndFilename()
     {
-        return $this->baseRenderingContext->getTemplatePaths()->resolveTemplateFileForControllerAndActionAndFormat($this->request->getControllerName(), $this->request->getControllerActionName(), $this->request->getFormat());
+        return $this->request
+            ? $this->baseRenderingContext
+                ->getTemplatePaths()
+                ->resolveTemplateFileForControllerAndActionAndFormat(
+                    $this->request->getControllerName(),
+                    $this->request->getControllerActionName(),
+                    $this->request->getFormat()
+                )
+            : null;
     }
 
     /**
@@ -225,7 +237,7 @@ public function setLayoutRootPaths(array $layoutRootPaths)
     /**
      * Resolves the layout root to be used inside other paths.
      *
-     * @return array Fluid layout root paths
+     * @return array<string> Fluid layout root paths
      * @throws InvalidTemplateResourceException
      * @api
      */
@@ -262,7 +274,7 @@ public function setPartialRootPaths(array $partialRootPaths)
     /**
      * Returns the absolute path to the folder that contains Fluid partial files
      *
-     * @return array Fluid partial root paths
+     * @return array<string> Fluid partial root paths
      * @throws InvalidTemplateResourceException
      * @api
      */
diff --git a/Neos.FluidAdaptor/Classes/View/TemplatePaths.php b/Neos.FluidAdaptor/Classes/View/TemplatePaths.php
index ee45bae7eb..6c577db4ae 100644
--- a/Neos.FluidAdaptor/Classes/View/TemplatePaths.php
+++ b/Neos.FluidAdaptor/Classes/View/TemplatePaths.php
@@ -52,7 +52,7 @@ class TemplatePaths extends \TYPO3Fluid\Fluid\View\TemplatePaths
     ];
 
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $options = [];
 
@@ -61,6 +61,9 @@ class TemplatePaths extends \TYPO3Fluid\Fluid\View\TemplatePaths
      */
     protected $packageManager;
 
+    /**
+     * @param array<string,mixed> $options
+     */
     public function __construct(array $options = [])
     {
         foreach ($options as $optionName => $optionValue) {
@@ -71,7 +74,7 @@ public function __construct(array $options = [])
     /**
      * @param PackageManager $packageManager
      */
-    public function injectPackageManager(PackageManager $packageManager)
+    public function injectPackageManager(PackageManager $packageManager): void
     {
         $this->packageManager = $packageManager;
     }
@@ -87,7 +90,7 @@ public function getTemplateRootPathPattern(): string
     /**
      * @param string $templateRootPathPattern
      */
-    public function setTemplateRootPathPattern(string $templateRootPathPattern)
+    public function setTemplateRootPathPattern(string $templateRootPathPattern): void
     {
         $this->templateRootPathPattern = $templateRootPathPattern;
     }
@@ -95,7 +98,7 @@ public function setTemplateRootPathPattern(string $templateRootPathPattern)
     /**
      * @param string $layoutRootPathPattern
      */
-    public function setLayoutRootPathPattern(string $layoutRootPathPattern)
+    public function setLayoutRootPathPattern(string $layoutRootPathPattern): void
     {
         $this->layoutRootPathPattern = $layoutRootPathPattern;
     }
@@ -103,7 +106,7 @@ public function setLayoutRootPathPattern(string $layoutRootPathPattern)
     /**
      * @param string $partialRootPathPattern
      */
-    public function setPartialRootPathPattern(string $partialRootPathPattern)
+    public function setPartialRootPathPattern(string $partialRootPathPattern): void
     {
         $this->partialRootPathPattern = $partialRootPathPattern;
     }
@@ -111,7 +114,7 @@ public function setPartialRootPathPattern(string $partialRootPathPattern)
     /**
      * @param string $templateRootPath
      */
-    public function setTemplateRootPath($templateRootPath)
+    public function setTemplateRootPath($templateRootPath): void
     {
         $this->templateRootPaths = [$templateRootPath];
     }
@@ -119,7 +122,7 @@ public function setTemplateRootPath($templateRootPath)
     /**
      * Resolves the template root to be used inside other paths.
      *
-     * @return array Path(s) to template root directory
+     * @return array<string> Path(s) to template root directory
      */
     public function getTemplateRootPaths()
     {
@@ -140,7 +143,7 @@ public function getTemplateRootPaths()
     }
 
     /**
-     * @return array
+     * @return array<string>
      */
     public function getLayoutRootPaths()
     {
@@ -160,7 +163,10 @@ public function getLayoutRootPaths()
         return [$layoutRootPath];
     }
 
-    public function getPartialRootPaths()
+    /**
+     * @return array<string>
+     */
+    public function getPartialRootPaths(): array
     {
         if ($this->partialRootPaths !== []) {
             return $this->partialRootPaths;
@@ -181,7 +187,7 @@ public function getPartialRootPaths()
     /**
      * @param string $layoutRootPath
      */
-    public function setLayoutRootPath($layoutRootPath)
+    public function setLayoutRootPath($layoutRootPath): void
     {
         $this->layoutRootPaths = [$layoutRootPath];
     }
@@ -189,7 +195,7 @@ public function setLayoutRootPath($layoutRootPath)
     /**
      * @param string $partialRootPath
      */
-    public function setPartialRootPath($partialRootPath)
+    public function setPartialRootPath($partialRootPath): void
     {
         $this->partialRootPaths = [$partialRootPath];
     }
@@ -205,7 +211,7 @@ public function getPatternReplacementVariables()
     /**
      * @param string[] $patternReplacementVariables
      */
-    public function setPatternReplacementVariables($patternReplacementVariables)
+    public function setPatternReplacementVariables($patternReplacementVariables): void
     {
         $this->patternReplacementVariables = $patternReplacementVariables;
     }
@@ -389,10 +395,10 @@ protected function sanitizePath($path)
      * replaced by the current request format, and once with ."@format" stripped off.
      *
      * @param string $pattern Pattern to be resolved
-     * @param array $patternReplacementVariables The variables to replace in the pattern
+     * @param array<string,mixed> $patternReplacementVariables The variables to replace in the pattern
      * @param boolean $bubbleControllerAndSubpackage if true, then we successively split off parts from "@controller" and "@subpackage" until both are empty.
      * @param boolean $formatIsOptional if true, then half of the resulting strings will have ."@format" stripped off, and the other half will have it.
-     * @return array unix style paths
+     * @return array<mixed> unix style paths
      */
     protected function expandGenericPathPattern($pattern, array $patternReplacementVariables, $bubbleControllerAndSubpackage, $formatIsOptional)
     {
@@ -426,10 +432,10 @@ protected function expandGenericPathPattern($pattern, array $patternReplacementV
     }
 
     /**
-     * @param array $paths
+     * @param array<mixed> $paths
      * @param string $variableName
      * @param string $variableValue
-     * @return array
+     * @return array<mixed>
      */
     protected function replacePatternVariable($paths, $variableName, $variableValue)
     {
@@ -441,11 +447,11 @@ protected function replacePatternVariable($paths, $variableName, $variableValue)
     }
 
     /**
-     * @param array $paths
+     * @param array<string> $paths
      * @param string $controllerName
      * @param string $subPackageKey
      * @param bool $bubbleControllerAndSubpackage
-     * @return array
+     * @return array<string>
      */
     protected function expandSubPackageAndController(array $paths, string $controllerName, string $subPackageKey = '', bool $bubbleControllerAndSubpackage = false): array
     {
@@ -460,7 +466,7 @@ protected function expandSubPackageAndController(array $paths, string $controlle
         $numberOfSubpackageParts = count($subpackageKeyParts);
         $subpackageReplacements = [];
         for ($i = 0; $i <= $numberOfSubpackageParts; $i++) {
-            $subpackageReplacements[] = implode('/', ($i < 0 ? $subpackageKeyParts : array_slice($subpackageKeyParts, $i)));
+            $subpackageReplacements[] = implode('/', array_slice($subpackageKeyParts, $i));
         }
         $paths = $this->expandPatterns($paths, '@subpackage', $subpackageReplacements);
 
@@ -476,10 +482,10 @@ protected function expandSubPackageAndController(array $paths, string $controlle
      * Expands the given $patterns by adding an array element for each $replacement
      * replacing occurrences of $search.
      *
-     * @param array $patterns
+     * @param array<string> $patterns
      * @param string $search
-     * @param array $replacements
-     * @return array
+     * @param array<string> $replacements
+     * @return array<int,string>
      */
     protected function expandPatterns(array $patterns, string $search, array $replacements): array
     {
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/DebugViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/DebugViewHelper.php
index 0b189fa7b2..39d42bc727 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/DebugViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/DebugViewHelper.php
@@ -78,6 +78,6 @@ public function render()
             $expressionToExamine = (is_object($expressionToExamine) ? get_class($expressionToExamine) : gettype($expressionToExamine));
         }
 
-        return \Neos\Flow\var_dump($expressionToExamine, $this->arguments['title'], true);
+        return \Neos\Flow\var_dump($expressionToExamine, $this->arguments['title'], true) ?: '';
     }
 }
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/FlashMessagesViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/FlashMessagesViewHelper.php
index 5198e6ed28..73ccbe633e 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/FlashMessagesViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/FlashMessagesViewHelper.php
@@ -105,7 +105,7 @@ public function render()
      * Render the flash messages as unsorted list. This is triggered if no "as" argument is given
      * to the ViewHelper.
      *
-     * @param list<Message> $flashMessages
+     * @param array<Message> $flashMessages
      * @return string
      */
     protected function renderAsList(array $flashMessages)
@@ -131,7 +131,7 @@ protected function renderAsList(array $flashMessages)
      * the flash messages are stored in the template inside the variable specified
      * in "as".
      *
-     * @param array $flashMessages
+     * @param array<Message> $flashMessages
      * @param string $as
      * @return string
      */
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Form/AbstractFormFieldViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Form/AbstractFormFieldViewHelper.php
index 489844b745..a3da57a863 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Form/AbstractFormFieldViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Form/AbstractFormFieldViewHelper.php
@@ -84,7 +84,6 @@ protected function getNameWithoutPrefix(): string
             $name = $this->arguments['name'];
         }
         if ($this->hasArgument('value')) {
-            /** @var object $value */
             $value = $this->arguments['value'];
             $multiple = $this->hasArgument('multiple') && $this->arguments['multiple'] === true;
             if (!$multiple
@@ -223,7 +222,7 @@ protected function getPropertyPath(): string
 
             return $formObjectName . '.' . $this->arguments['property'];
         }
-        return rtrim(preg_replace('/(\]\[|\[|\])/', '.', $this->getNameWithoutPrefix()), '.');
+        return rtrim(preg_replace('/(\]\[|\[|\])/', '.', $this->getNameWithoutPrefix()) ?: '', '.');
     }
 
     /**
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Form/AbstractFormViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Form/AbstractFormViewHelper.php
index 60aa6d6da6..c58c50daa5 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Form/AbstractFormViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Form/AbstractFormViewHelper.php
@@ -41,7 +41,7 @@ public function injectPersistenceManager(PersistenceManagerInterface $persistenc
     /**
      * Prefixes / namespaces the given name with the form field prefix
      *
-     * @param string $fieldName field name to be prefixed
+     * @param ?string $fieldName field name to be prefixed
      * @return string namespaced field name
      */
     protected function prefixFieldName($fieldName)
@@ -68,13 +68,13 @@ protected function prefixFieldName($fieldName)
      * Renders a hidden form field containing the technical identity of the given object.
      *
      * @param object $object Object to create the identity field for
-     * @param string $name Name
+     * @param ?string $name Name
      * @return string A hidden field containing the Identity (UUID in Flow) of the given object or empty string if the object is unknown to the persistence framework
      * @see \Neos\Flow\Mvc\Controller\Argument::setValue()
      */
-    protected function renderHiddenIdentityField($object, $name)
+    protected function renderHiddenIdentityField(object $object, $name)
     {
-        if (!is_object($object) || $this->persistenceManager->isNewObject($object)) {
+        if ($this->persistenceManager->isNewObject($object) || $name === null) {
             return '';
         }
         $identifier = $this->persistenceManager->getIdentifierByObject($object);
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Form/CheckboxViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Form/CheckboxViewHelper.php
index d7d4e3b574..d1fc34c4fb 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Form/CheckboxViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Form/CheckboxViewHelper.php
@@ -98,7 +98,11 @@ public function render()
             if ($checked === null) {
                 $checked = false;
                 foreach ($propertyValue as $value) {
-                    if (TypeHandling::isSimpleType(TypeHandling::getTypeForValue($value))) {
+                    $typeForValue = TypeHandling::getTypeForValue($value);
+                    if ($typeForValue === null) {
+                        continue;
+                    }
+                    if (TypeHandling::isSimpleType($typeForValue)) {
                         $checked = $valueAttribute === $value;
                     } else {
                         // assume an entity
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Form/SelectViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Form/SelectViewHelper.php
index a2dde44370..f9c0f08933 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Form/SelectViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Form/SelectViewHelper.php
@@ -200,7 +200,7 @@ public function render()
     /**
      * Render the option tags.
      *
-     * @param array $options the options for the form.
+     * @param array<mixed> $options the options for the form.
      * @return string rendered tags.
      */
     protected function renderOptionTags($options)
@@ -227,7 +227,7 @@ protected function renderOptionTags($options)
     /**
      * Render the option tags.
      *
-     * @return array an associative array of options, key will be the value of the option tag
+     * @return array<string,mixed> an associative array of options, key will be the value of the option tag
      * @throws ViewHelper\Exception
      */
     protected function getOptions()
@@ -354,6 +354,7 @@ protected function getOptionValueScalar($valueElement)
             } elseif ($this->persistenceManager->getIdentifierByObject($valueElement) !== null) {
                 return $this->persistenceManager->getIdentifierByObject($valueElement);
             } else {
+                /** @phpstan-ignore cast.string (we'll try anyway -.-) */
                 return (string)$valueElement;
             }
         } else {
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/FormViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/FormViewHelper.php
index 9d627d6dcf..3500474fbb 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/FormViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/FormViewHelper.php
@@ -299,7 +299,7 @@ protected function renderHiddenReferrerFields()
         $result = chr(10);
         $request = $this->controllerContext->getRequest();
         $argumentNamespace = null;
-        if ($request instanceof ActionRequest && $request->isMainRequest() === false) {
+        if ($request->isMainRequest() === false) {
             $argumentNamespace = $request->getArgumentNamespace();
 
             $referrer = [
@@ -313,13 +313,10 @@ protected function renderHiddenReferrerFields()
                 $referrerValue = $referrerValue ? htmlspecialchars($referrerValue) : '';
                 $result .= '<input type="hidden" name="' . $argumentNamespace . '[__referrer][' . $referrerKey . ']" value="' . $referrerValue . '" />' . chr(10);
             }
+            /** @var ActionRequest $request we know this since $request is not the main request */
             $request = $request->getParentRequest();
         }
 
-        if ($request === null) {
-            throw new \RuntimeException('No ActionRequest could be found to evaluate form argument namespace.', 1565945918);
-        }
-
         $arguments = $request->getArguments();
         if ($argumentNamespace !== null && isset($arguments[$argumentNamespace])) {
             // A sub request was there; thus we can unset the sub requests arguments,
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/BytesViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/BytesViewHelper.php
index 76a4b946e1..a538a7d88d 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/BytesViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/BytesViewHelper.php
@@ -72,7 +72,7 @@ class BytesViewHelper extends AbstractLocaleAwareViewHelper
 
     /**
      * @param float $bytes
-     * @return array<int, float|string>
+     * @return array{0: float, 1: string}
      */
     protected static function maximizeUnit(float $bytes): array
     {
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/CaseViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/CaseViewHelper.php
index 9dc3ecd2c2..8eefa16a80 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/CaseViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/CaseViewHelper.php
@@ -123,7 +123,7 @@ public function render()
     }
 
     /**
-     * @param array $arguments
+     * @param array<string,mixed> $arguments
      * @param \Closure $renderChildrenClosure
      * @param RenderingContextInterface $renderingContext
      * @return string
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/CropViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/CropViewHelper.php
index 4ab2986948..e9de2cb5be 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/CropViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/CropViewHelper.php
@@ -78,7 +78,7 @@ public function render()
     }
 
     /**
-     * @param array $arguments
+     * @param array<string,mixed> $arguments
      * @param \Closure $renderChildrenClosure
      * @param RenderingContextInterface $renderingContext
      * @return string
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/HtmlentitiesDecodeViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/HtmlentitiesDecodeViewHelper.php
index 0316b42dcc..660c7f2fee 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/HtmlentitiesDecodeViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/HtmlentitiesDecodeViewHelper.php
@@ -79,7 +79,7 @@ public function render()
     /**
      * Applies html_entity_decode() on the specified value.
      *
-     * @param array $arguments
+     * @param array<string,mixed> $arguments
      * @param \Closure $renderChildrenClosure
      * @param RenderingContextInterface $renderingContext
      * @return string|mixed
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/HtmlentitiesViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/HtmlentitiesViewHelper.php
index a1d67c8532..0f0dbe84ed 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/HtmlentitiesViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/HtmlentitiesViewHelper.php
@@ -79,7 +79,7 @@ public function render()
     /**
      * Applies htmlentities() on the specified value.
      *
-     * @param array $arguments
+     * @param array<string,mixed> $arguments
      * @param \Closure $renderChildrenClosure
      * @param RenderingContextInterface $renderingContext
      * @return string|mixed
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/JsonViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/JsonViewHelper.php
index 87c216d4d5..d8c7b228e4 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/JsonViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/JsonViewHelper.php
@@ -86,7 +86,7 @@ public function render()
             $options = $options | JSON_FORCE_OBJECT;
         }
 
-        return json_encode($value, $options);
+        return json_encode($value, $options | JSON_THROW_ON_ERROR);
     }
 
     /**
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/PaddingViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/PaddingViewHelper.php
index 476db7b55e..cc37d1f089 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/PaddingViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/PaddingViewHelper.php
@@ -79,7 +79,7 @@ public function render()
     /**
      * Applies str_pad() on the specified value.
      *
-     * @param array $arguments
+     * @param array<string,mixed> $arguments
      * @param \Closure $renderChildrenClosure
      * @param RenderingContextInterface $renderingContext
      * @return string
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/UrlencodeViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/UrlencodeViewHelper.php
index f312b713b2..f0650790bb 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Format/UrlencodeViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Format/UrlencodeViewHelper.php
@@ -72,7 +72,7 @@ public function render()
     /**
      * Applies rawurlencode() on the specified value.
      *
-     * @param array $arguments
+     * @param array<string,mixed> $arguments
      * @param \Closure $renderChildrenClosure
      * @param RenderingContextInterface $renderingContext
      * @return string|mixed
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/RenderChildrenViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/RenderChildrenViewHelper.php
index 9d35aca2ef..1041792388 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/RenderChildrenViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/RenderChildrenViewHelper.php
@@ -74,7 +74,7 @@ public function render(): string
         $widgetChildNodes = $this->getWidgetChildNodes();
 
         $this->addArgumentsToTemplateVariableContainer($this->arguments['arguments']);
-        $output = $widgetChildNodes->evaluate($renderingContext);
+        $output = $widgetChildNodes?->evaluate($renderingContext) ?: '';
         $this->removeArgumentsFromTemplateVariableContainer($this->arguments['arguments']);
 
         return $output;
@@ -97,10 +97,10 @@ protected function getWidgetRenderingContext(): RenderingContextInterface
     }
 
     /**
-     * @return RootNode
+     * @return ?RootNode
      * @throws WidgetContextNotFoundException
      */
-    protected function getWidgetChildNodes(): RootNode
+    protected function getWidgetChildNodes(): ?RootNode
     {
         return $this->getWidgetContext()->getViewHelperChildNodes();
     }
@@ -123,7 +123,7 @@ protected function getWidgetContext(): WidgetContext
     /**
      * Add the given arguments to the TemplateVariableContainer of the widget.
      *
-     * @param array $arguments
+     * @param array<string,mixed> $arguments
      * @return void
      * @throws RenderingContextNotFoundException
      * @throws WidgetContextNotFoundException
@@ -139,7 +139,7 @@ protected function addArgumentsToTemplateVariableContainer(array $arguments): vo
     /**
      * Remove the given arguments from the TemplateVariableContainer of the widget.
      *
-     * @param array $arguments
+     * @param array<string,mixed> $arguments
      * @return void
      * @throws RenderingContextNotFoundException
      * @throws WidgetContextNotFoundException
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Security/IfAccessViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Security/IfAccessViewHelper.php
index 225621a2e7..a6d05335eb 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Security/IfAccessViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Security/IfAccessViewHelper.php
@@ -57,7 +57,7 @@ class IfAccessViewHelper extends AbstractConditionViewHelper
     /**
      * Initializes the "then" and "else" arguments
      */
-    public function initializeArguments()
+    public function initializeArguments(): void
     {
         parent::initializeArguments();
         $this->registerArgument('privilegeTarget', 'string', 'Condition expression conforming to Fluid boolean rules', true);
@@ -80,9 +80,9 @@ public function render()
     }
 
     /**
-     * @param array $arguments
+     * @param array<string,mixed> $arguments
      * @param \Closure $renderChildrenClosure
-     * @param RenderingContextInterface $renderingContext
+     * @param FlowAwareRenderingContextInterface&RenderingContextInterface $renderingContext
      * @return mixed
      */
     public static function renderStatic(array $arguments, \Closure $renderChildrenClosure, RenderingContextInterface $renderingContext)
@@ -91,28 +91,30 @@ public static function renderStatic(array $arguments, \Closure $renderChildrenCl
     }
 
     /**
-     * @param array|null $arguments
+     * @param array<string,mixed>|null $arguments
      * @param FlowAwareRenderingContextInterface&RenderingContextInterface $renderingContext
      * @return boolean
      */
     protected static function evaluateCondition($arguments, RenderingContextInterface $renderingContext)
     {
         $objectManager = $renderingContext->getObjectManager();
-        /** @var Context $securityContext */
         $securityContext = $objectManager->get(Context::class);
 
-        if ($securityContext !== null && !$securityContext->canBeInitialized()) {
+        if (!$securityContext->canBeInitialized()) {
             return false;
         }
         $privilegeManager = static::getPrivilegeManager($renderingContext);
-        return $privilegeManager->isPrivilegeTargetGranted($arguments['privilegeTarget'], $arguments['parameters'] ?? []);
+        $privilegeTarget = $arguments['privilegeTarget'] ?? null;
+        if (!is_string($privilegeTarget)) {
+            throw new \Exception('Missing privilegeTarget argument.', 1743848049);
+        }
+        return $privilegeManager->isPrivilegeTargetGranted($privilegeTarget, $arguments['parameters'] ?? []);
     }
 
     /**
-     * @param RenderingContext $renderingContext
      * @return PrivilegeManagerInterface
      */
-    protected static function getPrivilegeManager(RenderingContext $renderingContext)
+    protected static function getPrivilegeManager(FlowAwareRenderingContextInterface $renderingContext)
     {
         $objectManager = $renderingContext->getObjectManager();
         return $objectManager->get(PrivilegeManagerInterface::class);
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Security/IfAuthenticatedViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Security/IfAuthenticatedViewHelper.php
index a7a78ae4b9..f7f6c6cb1f 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Security/IfAuthenticatedViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Security/IfAuthenticatedViewHelper.php
@@ -66,7 +66,7 @@ public function render()
     }
 
     /**
-     * @param null $arguments
+     * @param array<string,mixed>|null $arguments
      * @param FlowAwareRenderingContextInterface&RenderingContextInterface $renderingContext
      * @return bool
      */
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Security/IfHasRoleViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Security/IfHasRoleViewHelper.php
index 9be411ea51..5db4eeac33 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Security/IfHasRoleViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Security/IfHasRoleViewHelper.php
@@ -79,7 +79,7 @@ class IfHasRoleViewHelper extends AbstractConditionViewHelper
     /**
      * Initializes the "then" and "else" arguments
      */
-    public function initializeArguments()
+    public function initializeArguments(): void
     {
         parent::initializeArguments();
         $this->registerArgument('role', 'mixed', 'The role or role identifier.', true);
@@ -104,7 +104,7 @@ public function render()
     }
 
     /**
-     * @param array|null $arguments
+     * @param array<string,mixed>|null $arguments
      * @param FlowAwareRenderingContextInterface&RenderingContextInterface $renderingContext
      * @return boolean
      */
@@ -120,8 +120,8 @@ protected static function evaluateCondition($arguments, RenderingContextInterfac
             return false;
         }
 
-        $role = $arguments['role'];
-        $account = $arguments['account'];
+        $role = $arguments['role'] ?? null;
+        $account = $arguments['account'] ?? null;
         $packageKey = isset($arguments['packageKey']) ? $arguments['packageKey'] : $renderingContext->getControllerContext()->getRequest()->getControllerPackageKey();
 
         if (is_string($role)) {
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/TranslateViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/TranslateViewHelper.php
index c4c0d06f0b..540306e4da 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/TranslateViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/TranslateViewHelper.php
@@ -122,9 +122,7 @@ public function render()
         }
         if ($package === null) {
             $request = $this->renderingContext->getControllerContext()->getRequest();
-            if ($request instanceof ActionRequest) {
-                $package = $request->getControllerPackageKey();
-            }
+            $package = $request->getControllerPackageKey();
             if (empty($package)) {
                 throw new ViewHelperException(
                     'The current package key can\'t be resolved. Make sure to initialize the Fluid view with a proper ActionRequest and/or specify the "package" argument when using the f:translate ViewHelper',
@@ -151,7 +149,7 @@ public function render()
     /**
      * @param Translator $translator
      */
-    public function injectTranslator(Translator $translator)
+    public function injectTranslator(Translator $translator): void
     {
         $this->translator = $translator;
     }
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Uri/ResourceViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Uri/ResourceViewHelper.php
index 6254572c13..7caf99eec5 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Uri/ResourceViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Uri/ResourceViewHelper.php
@@ -100,7 +100,7 @@ public function render()
     }
 
     /**
-     * @param array $arguments
+     * @param array<string,mixed> $arguments
      * @param \Closure $renderChildrenClosure
      * @param FlowAwareRenderingContextInterface&RenderingContextInterface $renderingContext
      * @return string
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Validation/IfHasErrorsViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Validation/IfHasErrorsViewHelper.php
index 3efab8366c..ed51f1f7ce 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Validation/IfHasErrorsViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Validation/IfHasErrorsViewHelper.php
@@ -42,10 +42,9 @@
 class IfHasErrorsViewHelper extends AbstractConditionViewHelper
 {
     /**
-     * @return void
      * @throws \Neos\FluidAdaptor\Core\ViewHelper\Exception
      */
-    public function initializeArguments()
+    public function initializeArguments(): void
     {
         $this->registerArgument('then', 'mixed', 'Value to be returned if the condition if met.', false);
         $this->registerArgument('else', 'mixed', 'Value to be returned if the condition if not met.', false);
@@ -70,7 +69,7 @@ public function render()
     }
 
     /**
-     * @param null $arguments
+     * @param array<mixed> $arguments
      * @param FlowAwareRenderingContextInterface&RenderingContextInterface $renderingContext
      * @return boolean
      */
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/Controller/AutocompleteController.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/Controller/AutocompleteController.php
index 9dd40909a6..a9468b212a 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/Controller/AutocompleteController.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/Controller/AutocompleteController.php
@@ -21,7 +21,7 @@
 class AutocompleteController extends AbstractWidgetController
 {
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $configuration = ['limit' => 10];
 
@@ -82,6 +82,6 @@ public function autocompleteAction($term)
                 'value' => $val
             ];
         }
-        return json_encode($output);
+        return json_encode($output, JSON_THROW_ON_ERROR);
     }
 }
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/Controller/PaginateController.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/Controller/PaginateController.php
index 1778c2c0a1..a7b50ed016 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/Controller/PaginateController.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/Controller/PaginateController.php
@@ -26,7 +26,7 @@ class PaginateController extends AbstractWidgetController
     protected $objects;
 
     /**
-     * @var array
+     * @var array<string,mixed>
      */
     protected $configuration = ['itemsPerPage' => 10, 'insertAbove' => false, 'insertBelow' => true, 'maximumNumberOfLinks' => 99];
 
@@ -130,16 +130,24 @@ protected function calculateDisplayRange()
     }
 
     /**
-     * Returns an array with the keys "pages", "current", "numberOfPages", "nextPage" & "previousPage"
-     *
-     * @return array
+     * @return array{
+     *     pages: list<array{number: int, isCurrent: bool}>,
+     *     current: int,
+     *     numberOfPages: int,
+     *     displayRangeStart: float,
+     *     displayRangeEnd: float,
+     *     hasLessPages: bool,
+     *     hasMorePages: bool,
+     *     nextPage?: int,
+     *     previousPage?: int,
+     * }
      */
     protected function buildPagination()
     {
         $this->calculateDisplayRange();
         $pages = [];
         for ($i = $this->displayRangeStart; $i <= $this->displayRangeEnd; $i++) {
-            $pages[] = ['number' => $i, 'isCurrent' => ($i === $this->currentPage)];
+            $pages[] = ['number' => (int)$i, 'isCurrent' => ($i == $this->currentPage)];
         }
         $pagination = [
             'pages' => $pages,
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/LinkViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/LinkViewHelper.php
index 55de2b8c53..5a6800624a 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/LinkViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/LinkViewHelper.php
@@ -120,7 +120,7 @@ protected function getAjaxUri(): string
         } else {
             $arguments['__widgetId'] = $widgetContext->getAjaxWidgetIdentifier();
         }
-        return '?' . http_build_query($arguments, null, '&');
+        return '?' . http_build_query(data: $arguments, arg_separator: '&');
     }
 
     /**
diff --git a/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/UriViewHelper.php b/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/UriViewHelper.php
index f96c6702e2..a57cb01bcf 100644
--- a/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/UriViewHelper.php
+++ b/Neos.FluidAdaptor/Classes/ViewHelpers/Widget/UriViewHelper.php
@@ -104,7 +104,7 @@ protected function getAjaxUri(): string
         } else {
             $arguments['__widgetId'] = $widgetContext->getAjaxWidgetIdentifier();
         }
-        return '?' . http_build_query($arguments, null, '&');
+        return '?' . http_build_query(data: $arguments, arg_separator: '&');
     }
 
     /**
diff --git a/Neos.Http.Factories/Classes/FlowUploadedFile.php b/Neos.Http.Factories/Classes/FlowUploadedFile.php
index e9f5e296cb..be9592c68b 100644
--- a/Neos.Http.Factories/Classes/FlowUploadedFile.php
+++ b/Neos.Http.Factories/Classes/FlowUploadedFile.php
@@ -14,12 +14,12 @@ class FlowUploadedFile extends UploadedFile
      * This is either the persistent identifier of a previously submitted resource file
      * or an array with the "__identity" key set to the persistent identifier.
      *
-     * @var array|string
+     * @var array{__identity: string}|string|null
      */
     protected $originallySubmittedResource;
 
     /**
-     * @var string
+     * @var ?string
      */
     protected $collectionName;
 
@@ -27,7 +27,7 @@ class FlowUploadedFile extends UploadedFile
      * This is either the persistent identifier of a previously submitted resource file
      * or an array with the "__identity" key set to the persistent identifier.
      *
-     * @return array|string
+     * @return array{__identity: string}|string|null
      */
     public function getOriginallySubmittedResource()
     {
@@ -40,15 +40,15 @@ public function getOriginallySubmittedResource()
      * This is either the persistent identifier of a previously submitted resource file
      * or an array with the "__identity" key set to the persistent identifier.
      *
-     * @param array|string $originallySubmittedResource
+     * @param array{__identity: string}|string $originallySubmittedResource
      */
-    public function setOriginallySubmittedResource($originallySubmittedResource)
+    public function setOriginallySubmittedResource($originallySubmittedResource): void
     {
         $this->originallySubmittedResource = $originallySubmittedResource;
     }
 
     /**
-     * @return string
+     * @return ?string
      */
     public function getCollectionName()
     {
@@ -58,7 +58,7 @@ public function getCollectionName()
     /**
      * @param string $collectionName
      */
-    public function setCollectionName($collectionName)
+    public function setCollectionName($collectionName): void
     {
         $this->collectionName = $collectionName;
     }
diff --git a/Neos.Http.Factories/Classes/ServerRequestFactoryTrait.php b/Neos.Http.Factories/Classes/ServerRequestFactoryTrait.php
index b4be972e24..1208f5569f 100644
--- a/Neos.Http.Factories/Classes/ServerRequestFactoryTrait.php
+++ b/Neos.Http.Factories/Classes/ServerRequestFactoryTrait.php
@@ -56,6 +56,7 @@ public function __construct(
 
     /**
      * @inheritDoc
+     * @param array<mixed> $serverParams
      */
     public function createServerRequest(string $method, $uri, array $serverParams = []): ServerRequestInterface
     {
diff --git a/Neos.Http.Factories/Classes/StreamFactoryTrait.php b/Neos.Http.Factories/Classes/StreamFactoryTrait.php
index 6c79adcc84..f8201880bc 100644
--- a/Neos.Http.Factories/Classes/StreamFactoryTrait.php
+++ b/Neos.Http.Factories/Classes/StreamFactoryTrait.php
@@ -18,6 +18,9 @@ trait StreamFactoryTrait
     public function createStream(string $content = ''): StreamInterface
     {
         $fileHandle = fopen('php://temp', 'r+');
+        if (!is_resource($fileHandle)) {
+            throw new \Exception('unable to open php://temp', 1743846274);
+        }
         fwrite($fileHandle, $content);
         rewind($fileHandle);
 
@@ -30,11 +33,15 @@ public function createStream(string $content = ''): StreamInterface
     public function createStreamFromFile(string $filename, string $mode = 'r'): StreamInterface
     {
         $fileHandle = fopen($filename, $mode);
+        if (!is_resource($fileHandle)) {
+            throw new \Exception('unable to open ' . $filename, 1743846243);
+        }
         return $this->createStreamFromResource($fileHandle);
     }
 
     /**
      * @inheritDoc
+     * @param resource $resource
      */
     public function createStreamFromResource($resource): StreamInterface
     {
diff --git a/Neos.Kickstarter/Classes/Command/KickstartCommandController.php b/Neos.Kickstarter/Classes/Command/KickstartCommandController.php
index 246b927c0c..ef9dd18a25 100644
--- a/Neos.Kickstarter/Classes/Command/KickstartCommandController.php
+++ b/Neos.Kickstarter/Classes/Command/KickstartCommandController.php
@@ -49,7 +49,7 @@ class KickstartCommandController extends CommandController
      * @param string $packageType Optional package type, e.g. "neos-plugin"
      * @see neos.flow:package:create
      */
-    public function packageCommand($packageKey, $packageType = PackageInterface::DEFAULT_COMPOSER_TYPE)
+    public function packageCommand($packageKey, $packageType = PackageInterface::DEFAULT_COMPOSER_TYPE): void
     {
         $this->validatePackageKey($packageKey);
 
@@ -101,7 +101,7 @@ public function packageCommand($packageKey, $packageType = PackageInterface::DEF
      * @param boolean $force Overwrite any existing controller or template code. Regardless of this flag, the package, model and repository will never be overwritten.
      * @see neos.kickstarter:kickstart:commandcontroller
      */
-    public function actionControllerCommand($packageKey, $controllerName, $generateActions = false, $generateTemplates = true, $generateFusion = false, $generateRelated = false, $force = false)
+    public function actionControllerCommand($packageKey, $controllerName, $generateActions = false, $generateTemplates = true, $generateFusion = false, $generateRelated = false, $force = false): void
     {
         $subpackageName = '';
         if (strpos($packageKey, '/') !== false) {
@@ -195,7 +195,7 @@ public function actionControllerCommand($packageKey, $controllerName, $generateA
      * @param boolean $force Overwrite any existing controller.
      * @see neos.kickstarter:kickstart:actioncontroller
      */
-    public function commandControllerCommand($packageKey, $controllerName, $force = false)
+    public function commandControllerCommand($packageKey, $controllerName, $force = false): void
     {
         $this->validatePackageKey($packageKey);
         if (!$this->packageManager->isPackageAvailable($packageKey)) {
@@ -222,7 +222,7 @@ public function commandControllerCommand($packageKey, $controllerName, $force =
      * @param boolean $force Overwrite any existing model.
      * @see neos.kickstarter:kickstart:repository
      */
-    public function modelCommand($packageKey, $modelName, $force = false)
+    public function modelCommand($packageKey, $modelName, $force = false): void
     {
         $this->validatePackageKey($packageKey);
         if (!$this->packageManager->isPackageAvailable($packageKey)) {
@@ -264,7 +264,7 @@ public function modelCommand($packageKey, $modelName, $force = false)
      * @param boolean $force Overwrite any existing repository.
      * @see neos.kickstarter:kickstart:model
      */
-    public function repositoryCommand($packageKey, $modelName, $force = false)
+    public function repositoryCommand($packageKey, $modelName, $force = false): void
     {
         $this->validatePackageKey($packageKey);
         if (!$this->packageManager->isPackageAvailable($packageKey)) {
@@ -283,7 +283,7 @@ public function repositoryCommand($packageKey, $modelName, $force = false)
      *
      * @param string $packageKey The package key of the package for the documentation
      */
-    public function documentationCommand($packageKey)
+    public function documentationCommand($packageKey): void
     {
         $this->validatePackageKey($packageKey);
         if (!$this->packageManager->isPackageAvailable($packageKey)) {
@@ -303,7 +303,7 @@ public function documentationCommand($packageKey)
      *
      * @param string $packageKey The package key of the package for the translation
      * @param string $sourceLanguageKey The language key of the default language
-     * @param array $targetLanguageKeys Comma separated language keys for the target translations
+     * @param array<string> $targetLanguageKeys Comma separated language keys for the target translations
      * @return void
      */
     public function translationCommand($packageKey, $sourceLanguageKey, array $targetLanguageKeys = [])
@@ -339,7 +339,7 @@ protected function validatePackageKey($packageKey)
      * @param string $modelName
      * @see http://www.php.net/manual/en/reserved.keywords.php
      */
-    protected function validateModelName($modelName)
+    protected function validateModelName($modelName): void
     {
         if (Validation::isReservedKeyword($modelName)) {
             $this->outputLine('The name of the model cannot be one of the reserved words of PHP!');
diff --git a/Neos.Kickstarter/Classes/Service/GeneratorService.php b/Neos.Kickstarter/Classes/Service/GeneratorService.php
index e872b5f181..7ff7b55ba2 100644
--- a/Neos.Kickstarter/Classes/Service/GeneratorService.php
+++ b/Neos.Kickstarter/Classes/Service/GeneratorService.php
@@ -51,9 +51,9 @@ class GeneratorService
     protected $reflectionService;
 
     /**
-     * @var array
+     * @var array<int,string>
      */
-    protected $generatedFiles = [];
+    protected array $generatedFiles = [];
 
     /**
      * Generate a controller with the given name for the given package
@@ -63,7 +63,7 @@ class GeneratorService
      * @param string $controllerName The name of the new controller
      * @param boolean $fusionView If the controller should default to a FusionView
      * @param boolean $overwrite Overwrite any existing files?
-     * @return array An array of generated filenames
+     * @return array<int,string> An array of generated filenames
      */
     public function generateActionController($packageKey, $subpackage, $controllerName, $fusionView = false, $overwrite = false)
     {
@@ -102,7 +102,7 @@ public function generateActionController($packageKey, $subpackage, $controllerNa
      * @param string $controllerName The name of the new controller
      * @param boolean $fusionView If the controller should default to a FusionView
      * @param boolean $overwrite Overwrite any existing files?
-     * @return array An array of generated filenames
+     * @return array<int,string> An array of generated filenames
      */
     public function generateCrudController($packageKey, $subpackage, $controllerName, $fusionView = false, $overwrite = false)
     {
@@ -143,7 +143,7 @@ public function generateCrudController($packageKey, $subpackage, $controllerName
      * @param string $packageKey The package key of the controller's package
      * @param string $controllerName The name of the new controller
      * @param boolean $overwrite Overwrite any existing files?
-     * @return array An array of generated filenames
+     * @return array<int,string> An array of generated filenames
      */
     public function generateCommandController($packageKey, $controllerName, $overwrite = false)
     {
@@ -179,7 +179,7 @@ public function generateCommandController($packageKey, $controllerName, $overwri
      * @param string $viewName The name of the view
      * @param string $templateName The name of the view
      * @param boolean $overwrite Overwrite any existing files?
-     * @return array An array of generated filenames
+     * @return array<int,string> An array of generated filenames
      */
     public function generateView($packageKey, $subpackage, $controllerName, $viewName, $templateName, $overwrite = false)
     {
@@ -199,7 +199,9 @@ public function generateView($packageKey, $subpackage, $controllerName, $viewNam
         $contextVariables['modelFullClassName'] = '\\' . trim($baseNamespace, '\\') . ($subpackage != '' ? '\\' . $subpackage : '') . '\Domain\Model\\' . $controllerName;
         $contextVariables['modelClassName'] = ucfirst($contextVariables['modelName']);
 
-        $modelClassSchema = $this->reflectionService->getClassSchema($contextVariables['modelFullClassName']);
+        $modelClassSchema = class_exists($contextVariables['modelFullClassName'])
+            ? $this->reflectionService->getClassSchema($contextVariables['modelFullClassName'])
+            : null;
         if ($modelClassSchema !== null) {
             $contextVariables['properties'] = $modelClassSchema->getProperties();
             if (isset($contextVariables['properties']['Persistence_Object_Identifier'])) {
@@ -229,7 +231,7 @@ public function generateView($packageKey, $subpackage, $controllerName, $viewNam
      * @param string $packageKey The package key of the controller's package
      * @param string $layoutName The name of the layout
      * @param boolean $overwrite Overwrite any existing files?
-     * @return array An array of generated filenames
+     * @return array<int,string> An array of generated filenames
      */
     public function generateLayout($packageKey, $layoutName, $overwrite = false)
     {
@@ -261,7 +263,7 @@ public function generateLayout($packageKey, $layoutName, $overwrite = false)
      * @param string $viewName The name of the view
      * @param string $templateName The name of the view
      * @param boolean $overwrite Overwrite any existing files?
-     * @return array An array of generated filenames
+     * @return array<int,string> An array of generated filenames
      */
     public function generateFusion(string $packageKey, string $subpackage, string $controllerName, string $viewName, string $templateName, bool $overwrite = false): array
     {
@@ -281,7 +283,9 @@ public function generateFusion(string $packageKey, string $subpackage, string $c
         $contextVariables['modelFullClassName'] = '\\' . trim($baseNamespace, '\\') . ($subpackage != '' ? '\\' . $subpackage : '') . '\Domain\Model\\' . $controllerName;
         $contextVariables['modelClassName'] = ucfirst($contextVariables['modelName']);
 
-        $modelClassSchema = $this->reflectionService->getClassSchema($contextVariables['modelFullClassName']);
+        $modelClassSchema = class_exists($contextVariables['modelFullClassName'])
+            ? $this->reflectionService->getClassSchema($contextVariables['modelFullClassName'])
+            : null;
         if ($modelClassSchema !== null) {
             $contextVariables['properties'] = $modelClassSchema->getProperties();
             if (isset($contextVariables['properties']['Persistence_Object_Identifier'])) {
@@ -311,7 +315,7 @@ public function generateFusion(string $packageKey, string $subpackage, string $c
      * @param string $packageKey The package key of the controller's package
      * @param string $layoutName The name of the layout
      * @param boolean $overwrite Overwrite any existing files?
-     * @return array An array of generated filenames
+     * @return array<int,string> An array of generated filenames
      */
     public function generatePrototype(string $packageKey, string $layoutName, bool $overwrite = false): array
     {
@@ -340,9 +344,9 @@ public function generatePrototype(string $packageKey, string $layoutName, bool $
      *
      * @param string $packageKey The package key of the controller's package
      * @param string $modelName The name of the new model
-     * @param array $fieldDefinitions The field definitions
+     * @param array<mixed> $fieldDefinitions The field definitions
      * @param boolean $overwrite Overwrite any existing files?
-     * @return array An array of generated filenames
+     * @return array<int,string> An array of generated filenames
      */
     public function generateModel($packageKey, $modelName, array $fieldDefinitions, $overwrite = false)
     {
@@ -378,7 +382,7 @@ public function generateModel($packageKey, $modelName, array $fieldDefinitions,
      * @param string $packageKey The package key of the controller's package
      * @param string $modelName The name of the new model fpr which to generate the test
      * @param boolean $overwrite Overwrite any existing files?
-     * @return array An array of generated filenames
+     * @return array<int,string> An array of generated filenames
      */
     public function generateTestsForModel($packageKey, $modelName, $overwrite = false)
     {
@@ -411,7 +415,7 @@ public function generateTestsForModel($packageKey, $modelName, $overwrite = fals
      * @param string $packageKey The package key
      * @param string $modelName The name of the model
      * @param boolean $overwrite Overwrite any existing files?
-     * @return array An array of generated filenames
+     * @return array<int,string> An array of generated filenames
      */
     public function generateRepository($packageKey, $modelName, $overwrite = false)
     {
@@ -443,7 +447,7 @@ public function generateRepository($packageKey, $modelName, $overwrite = false)
      * Generate a documentation skeleton for the package key
      *
      * @param string $packageKey The package key
-     * @return array An array of generated filenames
+     * @return array<int,string> An array of generated filenames
      */
     public function generateDocumentation($packageKey)
     {
@@ -459,7 +463,7 @@ public function generateDocumentation($packageKey)
         $templatePathAndFilename = 'resource://Neos.Kickstarter/Private/Generator/Documentation/Makefile';
         $fileContent = file_get_contents($templatePathAndFilename);
         $targetPathAndFilename = $documentationPath . '/Makefile';
-        $this->generateFile($targetPathAndFilename, $fileContent);
+        $this->generateFile($targetPathAndFilename, $fileContent ?: '');
 
         $templatePathAndFilename = 'resource://Neos.Kickstarter/Private/Generator/Documentation/index.rst';
         $fileContent = $this->renderTemplate($templatePathAndFilename, $contextVariables);
@@ -481,8 +485,8 @@ public function generateDocumentation($packageKey)
      *
      * @param string $packageKey
      * @param string $sourceLanguageKey
-     * @param array $targetLanguageKeys
-     * @return array An array of generated filenames
+     * @param array<string> $targetLanguageKeys
+     * @return array<int,string> An array of generated filenames
      */
     public function generateTranslation($packageKey, $sourceLanguageKey, array $targetLanguageKeys = [])
     {
@@ -516,9 +520,9 @@ public function generateTranslation($packageKey, $sourceLanguageKey, array $targ
     /**
      * Normalize types and prefix types with namespaces
      *
-     * @param array $fieldDefinitions The field definitions
+     * @param array<mixed> $fieldDefinitions The field definitions
      * @param string $namespace The namespace
-     * @return array The normalized and type converted field definitions
+     * @return array<mixed> The normalized and type converted field definitions
      */
     protected function normalizeFieldDefinitions(array $fieldDefinitions, $namespace = '')
     {
@@ -574,7 +578,7 @@ protected function generateFile($targetPathAndFilename, $fileContent, $force = f
      * Render the given template file with the given variables
      *
      * @param string $templatePathAndFilename
-     * @param array $contextVariables
+     * @param array<mixed> $contextVariables
      * @return string
      * @throws \Neos\FluidAdaptor\Core\Exception
      */
@@ -588,7 +592,7 @@ protected function renderTemplate($templatePathAndFilename, array $contextVariab
 
     /**
      * @param PackageInterface $package
-     * @return array
+     * @return array<mixed>
      */
     protected function getPrimaryNamespaceAndEntryPath(PackageInterface $package)
     {
diff --git a/Neos.Kickstarter/Classes/Utility/Inflector.php b/Neos.Kickstarter/Classes/Utility/Inflector.php
index ed402234f7..49fa0eb222 100644
--- a/Neos.Kickstarter/Classes/Utility/Inflector.php
+++ b/Neos.Kickstarter/Classes/Utility/Inflector.php
@@ -56,6 +56,6 @@ public function humanizeCamelCase($camelCased, $lowercase = false)
      */
     protected function spacify($camelCased, $glue = ' ')
     {
-        return preg_replace('/([a-z0-9])([A-Z])/', '$1' . $glue . '$2', $camelCased);
+        return preg_replace('/([a-z0-9])([A-Z])/', '$1' . $glue . '$2', $camelCased) ?: '';
     }
 }
diff --git a/Neos.Utility.Arrays/Classes/Arrays.php b/Neos.Utility.Arrays/Classes/Arrays.php
index 71a44f2aeb..dc765df08b 100644
--- a/Neos.Utility.Arrays/Classes/Arrays.php
+++ b/Neos.Utility.Arrays/Classes/Arrays.php
@@ -22,9 +22,9 @@ abstract class Arrays
      * Explodes a $string delimited by $delimiter and passes each item in the array through intval().
      * Corresponds to explode(), but with conversion to integers for all values.
      *
-     * @param string $delimiter Delimiter string to explode with
+     * @param non-empty-string $delimiter Delimiter string to explode with
      * @param string $string The string to explode
-     * @return array Exploded values, all converted to integers
+     * @return array<mixed> Exploded values, all converted to integers
      */
     public static function integerExplode(string $delimiter, string $string): array
     {
@@ -41,10 +41,10 @@ public static function integerExplode(string $delimiter, string $string): array
      * Explodes a string and trims all values for whitespace in the ends.
      * If $onlyNonEmptyValues is set, then all blank ('') values are removed.
      *
-     * @param string $delimiter Delimiter string to explode with
+     * @param non-empty-string $delimiter Delimiter string to explode with
      * @param string $string The string to explode
      * @param boolean $onlyNonEmptyValues If disabled, even empty values (='') will be set in output
-     * @return array Exploded values
+     * @return array<mixed> Exploded values
      */
     public static function trimExplode(string $delimiter, string $string, bool $onlyNonEmptyValues = true): array
     {
@@ -64,11 +64,11 @@ public static function trimExplode(string $delimiter, string $string, bool $only
      * in the first array ($firstArray) with the values of the second array ($secondArray) in case of identical keys,
      * ie. keeping the values of the second.
      *
-     * @param array $firstArray First array
-     * @param array $secondArray Second array, overruling the first array
+     * @param array<mixed> $firstArray First array
+     * @param array<mixed> $secondArray Second array, overruling the first array
      * @param boolean $dontAddNewKeys If set, keys that are NOT found in $firstArray (first array) will not be set. Thus only existing value can/will be overruled from second array.
      * @param boolean $emptyValuesOverride If set (which is the default), values from $secondArray will overrule if they are empty (according to PHP's empty() function)
-     * @return array Resulting array where $secondArray values has overruled $firstArray values
+     * @return array<mixed> Resulting array where $secondArray values has overruled $firstArray values
      */
     public static function arrayMergeRecursiveOverrule(array $firstArray, array $secondArray, bool $dontAddNewKeys = false, bool $emptyValuesOverride = true): array
     {
@@ -109,13 +109,13 @@ public static function arrayMergeRecursiveOverrule(array $firstArray, array $sec
      * Merges two arrays recursively and "binary safe" (integer keys are overridden as well), overruling similar values in the first array ($firstArray) with the values of the second array ($secondArray)
      * In case of identical keys, ie. keeping the values of the second. The given $toArray closure will be used if one of the two array keys contains an array and the other not. It should return an array.
      *
-     * @param array $firstArray First array
-     * @param array $secondArray Second array, overruling the first array
+     * @param array<mixed> $firstArray First array
+     * @param array<mixed> $secondArray Second array, overruling the first array
      * @param \Closure $toArray The given callable will get a value that is not an array and has to return an array.
      *                          This is to allow custom merging of simple types with (sub) arrays
      * @param \Closure|null $overrideFirst The given callable will determine whether the value of the first array should be overridden.
      *                                     It should have the following signature $callable($key, ?array $firstValue = null, ?array $secondValue = null): bool
-     * @return array Resulting array where $secondArray values has overruled $firstArray values
+     * @return array<mixed> Resulting array where $secondArray values has overruled $firstArray values
      */
     public static function arrayMergeRecursiveOverruleWithCallback(array $firstArray, array $secondArray, \Closure $toArray, ?\Closure $overrideFirst = null): array
     {
@@ -157,8 +157,7 @@ public static function arrayMergeRecursiveOverruleWithCallback(array $firstArray
     /**
      * Returns true if the given array contains elements of varying types
      *
-     * @param array $array
-     * @return boolean
+     * @param array<mixed> $array
      */
     public static function containsMultipleTypes(array $array): bool
     {
@@ -179,12 +178,12 @@ public static function containsMultipleTypes(array $array): bool
      * Replacement for array_reduce that allows any type for $initial (instead
      * of only integer)
      *
-     * @param array $array the array to reduce
-     * @param string $function the reduce function with the same order of parameters as in the native array_reduce (i.e. accumulator first, then current array element)
+     * @param array<mixed> $array the array to reduce
+     * @param callable $function the reduce function with the same order of parameters as in the native array_reduce (i.e. accumulator first, then current array element)
      * @param mixed $initial the initial accumulator value
      * @return mixed
      */
-    public static function array_reduce(array $array, string $function, $initial = null)
+    public static function array_reduce(array $array, callable $function, $initial = null)
     {
         $accumulator = $initial;
         foreach ($array as $value) {
@@ -196,8 +195,8 @@ public static function array_reduce(array $array, string $function, $initial = n
     /**
      * Returns the value of a nested array by following the specifed path.
      *
-     * @param array $array The array to traverse
-     * @param array|string $path The path to follow. Either a simple array of keys or a string in the format 'foo.bar.baz'
+     * @param array<mixed> $array The array to traverse
+     * @param array<mixed>|string $path The path to follow. Either a simple array of keys or a string in the format 'foo.bar.baz'
      * @return mixed The value found, NULL if the path didn't exist (note there is no way to distinguish between a found NULL value and "path not found")
      */
     public static function getValueByPath(array $array, array|string $path): mixed
@@ -222,8 +221,8 @@ public static function getValueByPath(array $array, array|string $path): mixed
      * See {@see ValueAccessor}
      *
      * @internal experimental feature, not stable API
-     * @param array $array The array to traverse
-     * @param array|string $path The path to follow. Either a simple array of keys or a string in the format 'foo.bar.baz'
+     * @param array<mixed> $array The array to traverse
+     * @param array<mixed>|string $path The path to follow. Either a simple array of keys or a string in the format 'foo.bar.baz'
      * @return ValueAccessor
      */
     public static function getAccessorByPath(array $array, array|string $path): ValueAccessor
@@ -235,21 +234,16 @@ public static function getAccessorByPath(array $array, array|string $path): Valu
     /**
      * Sets the given value in a nested array or object by following the specified path.
      *
-     * @param array|\ArrayAccess $subject The array or ArrayAccess instance to work on
-     * @param array|string $path The path to follow. Either a simple array of keys or a string in the format 'foo.bar.baz'
+     * @param array<mixed>|\ArrayAccess<int|string, mixed> $subject The array or ArrayAccess instance to work on
+     * @param array<mixed>|string $path The path to follow. Either a simple array of keys or a string in the format 'foo.bar.baz'
      * @param mixed $value The value to set
-     * @return array|\ArrayAccess The modified array or object
+     * @return array<mixed>|\ArrayAccess<int|string, mixed> The modified array or object
      * @throws \InvalidArgumentException
      */
-    public static function setValueByPath($subject, $path, $value)
+    public static function setValueByPath(array|\ArrayAccess $subject, array|string $path, $value)
     {
-        if (!is_array($subject) && !($subject instanceof \ArrayAccess)) {
-            throw new \InvalidArgumentException('setValueByPath() expects $subject to be array or an object implementing \ArrayAccess, "' . (is_object($subject) ? get_class($subject) : gettype($subject)) . '" given.', 1306424308);
-        }
         if (is_string($path)) {
             $path = explode('.', $path);
-        } elseif (!is_array($path)) {
-            throw new \InvalidArgumentException('setValueByPath() expects $path to be string or array, "' . gettype($path) . '" given.', 1305111499);
         }
         $key = array_shift($path);
         if (count($path) === 0) {
@@ -266,17 +260,15 @@ public static function setValueByPath($subject, $path, $value)
     /**
      * Unsets an element/part of a nested array by following the specified path.
      *
-     * @param array $array The array
-     * @param array|string $path The path to follow. Either a simple array of keys or a string in the format 'foo.bar.baz'
-     * @return array The modified array
+     * @param array<mixed> $array The array
+     * @param array<mixed>|string $path The path to follow. Either a simple array of keys or a string in the format 'foo.bar.baz'
+     * @return array<mixed> The modified array
      * @throws \InvalidArgumentException
      */
-    public static function unsetValueByPath(array $array, $path): array
+    public static function unsetValueByPath(array $array, array|string $path): array
     {
         if (is_string($path)) {
             $path = explode('.', $path);
-        } elseif (!is_array($path)) {
-            throw new \InvalidArgumentException('unsetValueByPath() expects $path to be string or array, "' . gettype($path) . '" given.', 1305111513);
         }
         $key = array_shift($path);
         if (count($path) === 0) {
@@ -293,7 +285,7 @@ public static function unsetValueByPath(array $array, $path): array
     /**
      * Sorts multidimensional arrays by recursively calling ksort on its elements.
      *
-     * @param array $array the array to sort
+     * @param array<mixed> $array the array to sort
      * @param integer $sortFlags may be used to modify the sorting behavior using these values (see http://www.php.net/manual/en/function.sort.php)
      * @return boolean true on success, false on failure
      * @see asort()
@@ -314,7 +306,7 @@ public static function sortKeysRecursively(array &$array, int $sortFlags = \SORT
      * Recursively convert an object hierarchy into an associative array.
      *
      * @param mixed $subject An object or array of objects
-     * @return array The subject represented as an array
+     * @return array<mixed> The subject represented as an array
      * @throws \InvalidArgumentException
      */
     public static function convertObjectToArray($subject): array
@@ -336,8 +328,8 @@ public static function convertObjectToArray($subject): array
     /**
      * Recursively removes empty array elements.
      *
-     * @param array $array
-     * @return array the modified array
+     * @param array<mixed> $array
+     * @return array<mixed> the modified array
      */
     public static function removeEmptyElementsRecursively(array $array): array
     {
diff --git a/Neos.Utility.Arrays/Classes/PositionalArraySorter.php b/Neos.Utility.Arrays/Classes/PositionalArraySorter.php
index e900ddd58d..fd05be60ed 100644
--- a/Neos.Utility.Arrays/Classes/PositionalArraySorter.php
+++ b/Neos.Utility.Arrays/Classes/PositionalArraySorter.php
@@ -44,18 +44,33 @@
  */
 final class PositionalArraySorter
 {
+    /**
+     * @var array<mixed>
+     */
     private array $startKeys;
 
+    /**
+     * @var array<mixed>
+     */
     private array $middleKeys;
 
+    /**
+     * @var array<mixed>
+     */
     private array $endKeys;
 
+    /**
+     * @var array<mixed>
+     */
     private array $beforeKeys;
 
+    /**
+     * @var array<mixed>
+     */
     private array $afterKeys;
 
     /**
-     * @param array $subject The source array to sort
+     * @param array<mixed> $subject The source array to sort
      * @param string $positionPropertyPath optional property path to the string that contains the position
      * @param bool $removeNullValues if set to TRUE (default), null-values of the subject are removed
      */
@@ -69,7 +84,7 @@ public function __construct(
     /**
      * Returns a sorted copy of the subject array
      *
-     * @return array
+     * @return array<mixed>
      * @throws Exception\InvalidPositionException
      */
     public function toArray(): array
@@ -87,7 +102,7 @@ public function toArray(): array
      *
      * TODO Detect circles in after / before dependencies (#52185)
      *
-     * @return array an ordered list of keys
+     * @return array<mixed> an ordered list of keys
      * @throws Exception\InvalidPositionException if the positional string has an unsupported format
      */
     public function getSortedKeys(): array
@@ -112,6 +127,8 @@ public function getSortedKeys(): array
      * Extracts all "middle" keys from $arrayKeysWithPosition. Those are all keys with a numeric position.
      * The result is a multidimensional arrays where the KEY of each array is a PRIORITY and the VALUE is an array of matching KEYS
      * This also removes matching keys from the given $arrayKeysWithPosition
+     *
+     * @param array<mixed> $arrayKeysWithPosition
      */
     private function extractMiddleKeys(array &$arrayKeysWithPosition): void
     {
@@ -130,6 +147,8 @@ private function extractMiddleKeys(array &$arrayKeysWithPosition): void
      * Extracts all "start" keys from $arrayKeysWithPosition. Those are all keys with a position starting with "start"
      * The result is a multidimensional arrays where the KEY of each array is a PRIORITY and the VALUE is an array of matching KEYS
      * This also removes matching keys from the given $arrayKeysWithPosition
+     *
+     * @param array<mixed> $arrayKeysWithPosition
      */
     private function extractStartKeys(array &$arrayKeysWithPosition): void
     {
@@ -152,6 +171,8 @@ private function extractStartKeys(array &$arrayKeysWithPosition): void
      * Extracts all "end" keys from $arrayKeysWithPosition. Those are all keys with a position starting with "end"
      * The result is a multidimensional arrays where the KEY of each array is a PRIORITY and the VALUE is an array of matching KEYS
      * This also removes matching keys from the given $arrayKeysWithPosition
+     *
+     * @param array<mixed> $arrayKeysWithPosition
      */
     private function extractEndKeys(array &$arrayKeysWithPosition): void
     {
@@ -174,6 +195,9 @@ private function extractEndKeys(array &$arrayKeysWithPosition): void
      * Extracts all "before" keys from $arrayKeysWithPosition. Those are all keys with a position starting with "before"
      * The result is a multidimensional arrays where the KEY of each array is a PRIORITY and the VALUE is an array of matching KEYS
      * This also removes matching keys from the given $arrayKeysWithPosition
+     *
+     * @param array<mixed> $arrayKeysWithPosition
+     * @param array<mixed> $existingKeys
      */
     private function extractBeforeKeys(array &$arrayKeysWithPosition, array $existingKeys): void
     {
@@ -201,6 +225,9 @@ private function extractBeforeKeys(array &$arrayKeysWithPosition, array $existin
      * Extracts all "after" keys from $arrayKeysWithPosition. Those are all keys with a position starting with "after"
      * The result is a multidimensional arrays where the KEY of each array is a PRIORITY and the VALUE is an array of matching KEYS
      * This also removes matching keys from the given $arrayKeysWithPosition
+     *
+     * @param array<mixed> $arrayKeysWithPosition
+     * @param array<mixed> $existingKeys
      */
     private function extractAfterKeys(array &$arrayKeysWithPosition, array $existingKeys): void
     {
@@ -228,7 +255,7 @@ private function extractAfterKeys(array &$arrayKeysWithPosition, array $existing
      * Collect the array keys inside $this->subject with each position meta-argument.
      * If there is no position but the array is numerically ordered, we use the array index as position.
      *
-     * @return array an associative array where each key of $subject has a position string assigned
+     * @return array<mixed> an associative array where each key of $subject has a position string assigned
      */
     private function collectArrayKeysAndPositions(): array
     {
@@ -253,6 +280,8 @@ private function collectArrayKeysAndPositions(): array
 
     /**
      * Flattens start-, middle-, end-, before- and afterKeys to a single dimension and merges them together to a single array
+     *
+     * @return array<mixed>
      */
     private function generateSortedKeysMap(): array
     {
diff --git a/Neos.Utility.Arrays/Classes/ValueAccessor.php b/Neos.Utility.Arrays/Classes/ValueAccessor.php
index 060ee0c8d7..5bfb0e7852 100644
--- a/Neos.Utility.Arrays/Classes/ValueAccessor.php
+++ b/Neos.Utility.Arrays/Classes/ValueAccessor.php
@@ -47,6 +47,7 @@ public static function forValue(mixed $value): self
 
     /**
      * @internal You should use {@see ValueAccessor::forValue} instead
+     * @param array<mixed> $path
      */
     public static function forValueInPath(mixed $value, array|string $path): self
     {
@@ -97,6 +98,9 @@ public function classString(): string
         throw $this->createTypeError("is not a class-string");
     }
 
+    /**
+     * @return array<mixed>
+     */
     public function array(): array
     {
         if (is_array($this->value)) {
@@ -161,6 +165,9 @@ public function classStringOrNull(): ?string
         throw $this->createTypeError("is not a class-string");
     }
 
+    /**
+     * @return array<mixed>|null
+     */
     public function arrayOrNull(): ?array
     {
         if (is_array($this->value) || is_null($this->value)) {
@@ -182,7 +189,7 @@ public function instanceOfOrNull(string $className): ?object
         throw $this->createTypeError(sprintf('is not an instance of %s or null', $className));
     }
 
-    private function createTypeError($message): \UnexpectedValueException
+    private function createTypeError(string $message): \UnexpectedValueException
     {
         return new \UnexpectedValueException(get_debug_type($this->value) . ' ' . $message . ($this->additionalErrorMessage ? ' ' . $this->additionalErrorMessage : ''));
     }
diff --git a/Neos.Utility.Files/Classes/Files.php b/Neos.Utility.Files/Classes/Files.php
index b0ff9b5b91..136bbed8e4 100644
--- a/Neos.Utility.Files/Classes/Files.php
+++ b/Neos.Utility.Files/Classes/Files.php
@@ -32,7 +32,7 @@ public static function getUnixStylePath(string $path): string
         if (strpos($path, ':') === false) {
             return str_replace(['//', '\\'], '/', $path);
         }
-        return preg_replace('/^([a-z]{2,}):\//', '$1://', str_replace(['//', '\\'], '/', $path));
+        return preg_replace('/^([a-z]{2,}):\//', '$1://', str_replace(['//', '\\'], '/', $path)) ?: '';
     }
 
     /**
@@ -53,7 +53,7 @@ public static function getNormalizedPath(string $path): string
      * Note: trailing slashes will be removed, leading slashes won't.
      * Usage: concatenatePaths(array('dir1/dir2', 'dir3', 'file'))
      *
-     * @param array $paths the file paths to be combined. Last array element may include the filename.
+     * @param array<int,string> $paths the file paths to be combined. Last array element may include the filename.
      * @return string concatenated path without trailing slash.
      * @see getUnixStylePath()
      * @api
@@ -80,10 +80,10 @@ public static function concatenatePaths(array $paths): string
      * directories.
      *
      * @param string $path Path to the directory which shall be read
-     * @param string $suffix If specified, only filenames with this extension are returned (eg. ".php" or "foo.bar")
+     * @param ?string $suffix If specified, only filenames with this extension are returned (eg. ".php" or "foo.bar")
      * @param boolean $returnRealPath If turned on, all paths are resolved by calling realpath()
      * @param boolean $returnDotFiles If turned on, also files beginning with a dot will be returned
-     * @return array Filenames including full path
+     * @return array<int,string> Filenames including full path
      * @api
      */
     public static function readDirectoryRecursively(string $path, ?string $suffix = null, bool $returnRealPath = false, bool $returnDotFiles = false): array
@@ -122,7 +122,7 @@ public static function getRecursiveDirectoryGenerator(string $path, ?string $suf
                     if (is_dir($pathAndFilename)) {
                         array_push($directories, self::getNormalizedPath($pathAndFilename));
                     } elseif ($suffix === null || strpos(strrev($filename), strrev($suffix)) === 0) {
-                        yield static::getUnixStylePath(($returnRealPath === true) ? realpath($pathAndFilename) : $pathAndFilename);
+                        yield static::getUnixStylePath(($returnRealPath === true) ? realpath($pathAndFilename) ?: '' : $pathAndFilename);
                     }
                 }
                 closedir($handle);
@@ -153,6 +153,9 @@ public static function emptyDirectoryRecursively(string $path)
         } else {
             $directoryIterator = new \RecursiveDirectoryIterator($path);
             foreach ($directoryIterator as $fileInfo) {
+                if (is_string($fileInfo)) {
+                    continue;
+                }
                 if (!$fileInfo->isDir()) {
                     if (self::unlink($fileInfo->getPathname()) !== true) {
                         throw new FilesException('Could not unlink file "' . $fileInfo->getPathname() . '".', 1169047619);
@@ -322,14 +325,12 @@ public static function copyDirectoryRecursively(string $sourceDirectory, string
      */
     public static function getFileContents(string $pathAndFilename, int $flags = 0, $context = null, int $offset = 0, int $maximumLength = -1)
     {
-        if ($flags === true) {
-            $flags = FILE_USE_INCLUDE_PATH;
-        }
+        $useIncludePath = ($flags & FILE_USE_INCLUDE_PATH) === 1;
         try {
             if ($maximumLength > -1) {
-                $content = file_get_contents($pathAndFilename, $flags, $context, $offset, $maximumLength);
+                $content = file_get_contents($pathAndFilename, $useIncludePath, $context, $offset, $maximumLength);
             } else {
-                $content = file_get_contents($pathAndFilename, $flags, $context, $offset);
+                $content = file_get_contents($pathAndFilename, $useIncludePath, $context, $offset);
             }
         } catch (ErrorException $ignoredException) {
             $content = false;
@@ -386,7 +387,7 @@ public static function is_link(string $pathAndFilename): bool
             return false;
         }
         $normalizedPathAndFilename = strtolower(rtrim(self::getUnixStylePath($pathAndFilename), '/'));
-        $normalizedTargetPathAndFilename = strtolower(self::getUnixStylePath(realpath($pathAndFilename)));
+        $normalizedTargetPathAndFilename = strtolower(self::getUnixStylePath(realpath($pathAndFilename) ?: ''));
         if ($normalizedTargetPathAndFilename === '') {
             return false;
         }
@@ -431,20 +432,19 @@ public static function unlink(string $pathAndFilename): bool
     /**
      * Supported file size units for the byte conversion functions below
      *
-     * @var array
+     * @var array<string>
      */
-    protected static $sizeUnits = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
+    protected static array $sizeUnits = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
 
     /**
      * Converts an integer with a byte count into human-readable form
      *
-     * @param float|integer $bytes
-     * @param integer $decimals number of decimal places in the resulting string
-     * @param string $decimalSeparator decimal separator of the resulting string
-     * @param string $thousandsSeparator thousands separator of the resulting string
+     * @param integer|null $decimals number of decimal places in the resulting string
+     * @param string|null $decimalSeparator decimal separator of the resulting string
+     * @param string|null $thousandsSeparator thousands separator of the resulting string
      * @return string the size string, e.g. "1,024 MB"
      */
-    public static function bytesToSizeString($bytes, ?int $decimals = null, ?string $decimalSeparator = null, ?string $thousandsSeparator = null): string
+    public static function bytesToSizeString(float|int|string $bytes, ?int $decimals = null, ?string $decimalSeparator = null, ?string $thousandsSeparator = null): string
     {
         if (!is_int($bytes) && !is_float($bytes)) {
             if (is_numeric($bytes)) {
@@ -502,7 +502,7 @@ public static function sizeStringToBytes(string $sizeString): float
         if ($pow === false) {
             throw new FilesException(sprintf('Unknown file size unit "%s"', $matches['unit']), 1417695299);
         }
-        return $size * pow(2, (10 * $pow));
+        return $size * pow(2, (10 * (int)$pow));
     }
 
     /**
diff --git a/Neos.Utility.MediaTypes/Classes/MediaTypes.php b/Neos.Utility.MediaTypes/Classes/MediaTypes.php
index 249d21ced8..65c0db4f0c 100644
--- a/Neos.Utility.MediaTypes/Classes/MediaTypes.php
+++ b/Neos.Utility.MediaTypes/Classes/MediaTypes.php
@@ -33,7 +33,7 @@ abstract class MediaTypes
     /**
      * A map of file extensions to Internet Media Types
      *
-     * @var array
+     * @var array<string,string>
      */
     private static $extensionToMediaType = [
         '3dml' => 'text/vnd.in3d.3dml',
@@ -1027,7 +1027,7 @@ abstract class MediaTypes
     /**
      * A map of Internet Media Types to file extensions
      *
-     * @var array
+     * @var array<string,array<string>>
      */
     private static $mediaTypeToFileExtension = [
         'application/andrew-inset' => ['ez'],
@@ -1821,13 +1821,13 @@ public static function getMediaTypeFromFilename(string $filename): string
      * Returns a Media Type based on the file content
      *
      * @param string $fileContent The file content do determine the media type from
-     * @return string The IANA Internet Media Type
+     * @return string|null The IANA Internet Media Type
      */
-    public static function getMediaTypeFromFileContent(string $fileContent): string
+    public static function getMediaTypeFromFileContent(string $fileContent): ?string
     {
         $fileInfo = new \finfo(FILEINFO_MIME);
-        $mediaType = self::trimMediaType($fileInfo->buffer($fileContent));
-        return isset(self::$mediaTypeToFileExtension[$mediaType]) ? $mediaType : 'application/octet-stream';
+        $mediaType = self::trimMediaType($fileInfo->buffer($fileContent) ?: '');
+        return ($mediaType === null || isset(self::$mediaTypeToFileExtension[$mediaType])) ? $mediaType : 'application/octet-stream';
     }
 
     /**
@@ -1846,7 +1846,7 @@ public static function getFilenameExtensionFromMediaType(string $mediaType): str
      * Returns all possible filename extensions based on the given Media Type.
      *
      * @param string $mediaType The IANA Internet Media Type, for example "text/html"
-     * @return array The corresponding filename extensions, for example ("html", "htm")
+     * @return array<string> The corresponding filename extensions, for example ("html", "htm")
      * @api
      */
     public static function getFilenameExtensionsFromMediaType(string $mediaType): array
@@ -1867,7 +1867,7 @@ public static function getFilenameExtensionsFromMediaType(string $mediaType): ar
      * "parameters" => an array of parameter names and values, array("charset" => "UTF-8")
      *
      * @param string $rawMediaType The raw media type, for example "application/json; charset=UTF-8"
-     * @return array An associative array with parsed information
+     * @return array{type: string, subtype: string, parameters: array<string,string>} An associative array with parsed information
      */
     public static function parseMediaType(string $rawMediaType): array
     {
@@ -1921,9 +1921,9 @@ public static function mediaRangeMatches(string $mediaRange, string $mediaType):
      * and subtype in the format "type/subtype".
      *
      * @param string $rawMediaType The full media type, for example "application/json; charset=UTF-8"
-     * @return string Just the type and subtype, for example "application/json"
+     * @return string|null Just the type and subtype, for example "application/json"
      */
-    public static function trimMediaType(string $rawMediaType)
+    public static function trimMediaType(string $rawMediaType): ?string
     {
         $pieces = self::parseMediaType($rawMediaType);
         return trim(sprintf('%s/%s', $pieces['type'], $pieces['subtype']), '/') ?: null;
diff --git a/Neos.Utility.ObjectHandling/Classes/ObjectAccess.php b/Neos.Utility.ObjectHandling/Classes/ObjectAccess.php
index 89decda676..cb15a28b43 100644
--- a/Neos.Utility.ObjectHandling/Classes/ObjectAccess.php
+++ b/Neos.Utility.ObjectHandling/Classes/ObjectAccess.php
@@ -31,15 +31,15 @@ abstract class ObjectAccess
 {
     /**
      * Internal RuntimeCache for getGettablePropertyNames()
-     * @var array
+     * @var array<string<object>,array<int,string>>
      */
-    protected static $gettablePropertyNamesCache = [];
+    protected static array $gettablePropertyNamesCache = [];
 
     /**
      * Internal RuntimeCache for getPropertyInternal()
-     * @var array
+     * @var array<string,array{accessorMethod?: string, publicProperty?: string}>
      */
-    protected static $propertyGetterCache = [];
+    protected static array $propertyGetterCache = [];
 
     const ACCESS_GET = 0;
     const ACCESS_SET = 1;
@@ -58,22 +58,14 @@ abstract class ObjectAccess
      * - if public property exists, return the value of it.
      * - else, throw exception
      *
-     * @param mixed $subject Object or array to get the property from
+     * @param object|array<mixed> $subject Object or array to get the property from
      * @param string|integer $propertyName Name or index of the property to retrieve
      * @param boolean $forceDirectAccess Directly access property using reflection(!)
      * @return mixed Value of the property
-     * @throws \InvalidArgumentException in case $subject was not an object or $propertyName was not a string
      * @throws PropertyNotAccessibleException if the property was not accessible
      */
-    public static function getProperty($subject, $propertyName, bool $forceDirectAccess = false)
+    public static function getProperty(object|array $subject, string|int $propertyName, bool $forceDirectAccess = false)
     {
-        if (!is_object($subject) && !is_array($subject)) {
-            throw new \InvalidArgumentException('$subject must be an object or array, ' . gettype($subject) . ' given.', 1237301367);
-        }
-        if (!is_string($propertyName) && !is_int($propertyName)) {
-            throw new \InvalidArgumentException('Given property name/index is not of type string or integer.', 1231178303);
-        }
-
         $propertyExists = false;
         $propertyValue = self::getPropertyInternal($subject, $propertyName, $forceDirectAccess, $propertyExists);
         if ($propertyExists === true) {
@@ -91,14 +83,14 @@ public static function getProperty($subject, $propertyName, bool $forceDirectAcc
      * of type string you should use getProperty() instead.
      *
      * @param mixed $subject Object or array to get the property from
-     * @param string $propertyName name of the property to retrieve
+     * @param string|int $propertyName name of the property to retrieve
      * @param boolean $forceDirectAccess directly access property using reflection(!)
      * @param boolean $propertyExists (by reference) will be set to true if the specified property exists and is gettable
      * @return mixed Value of the property
      * @throws PropertyNotAccessibleException
      * @see getProperty()
      */
-    protected static function getPropertyInternal($subject, string $propertyName, bool $forceDirectAccess, bool &$propertyExists)
+    protected static function getPropertyInternal($subject, string|int $propertyName, bool $forceDirectAccess, bool &$propertyExists)
     {
         if ($subject === null) {
             return null;
@@ -111,7 +103,12 @@ protected static function getPropertyInternal($subject, string $propertyName, bo
             return null;
         }
 
+        if (is_int($propertyName)) {
+            throw new \InvalidArgumentException('Cannot use integer property names for objects', 1743799241);
+        }
+
         $propertyExists = true;
+        /** @var string $className safe for objects */
         $className = TypeHandling::getTypeForValue($subject);
 
         if ($forceDirectAccess === true) {
@@ -230,39 +227,33 @@ public static function getPropertyPath($subject, string $propertyPath)
      *   on it without checking if it existed.
      * - else, return false
      *
-     * @param mixed $subject The target object or array
+     * @template T of object
+     * @param array<mixed>|T &$subject The target object or array
      * @param string|integer $propertyName Name or index of the property to set
      * @param mixed $propertyValue Value of the property
      * @param boolean $forceDirectAccess directly access property using reflection(!)
+     * @param-out ($subject is array ? array<mixed> : T) $subject
      * @return boolean true if the property could be set, false otherwise
-     * @throws \InvalidArgumentException in case $object was not an object or $propertyName was not a string
      */
-    public static function setProperty(&$subject, $propertyName, $propertyValue, bool $forceDirectAccess = false): bool
+    public static function setProperty(array|object &$subject, string|int $propertyName, $propertyValue, bool $forceDirectAccess = false): bool
     {
-        if (!is_string($propertyName) && !is_int($propertyName)) {
-            throw new \InvalidArgumentException('Given property name/index is not of type string or integer.', 1231178878);
-        }
-
         if (is_array($subject)) {
             $subject[$propertyName] = $propertyValue;
             return true;
         }
 
-        if (!is_object($subject)) {
-            throw new \InvalidArgumentException('subject must be an object or array, ' . gettype($subject) . ' given.', 1237301368);
-        }
-
         if ($forceDirectAccess === true) {
             if (!is_string($propertyName)) {
                 throw new \InvalidArgumentException('Given property name is not of type string.', 1648244846);
             }
+            /** @var string $className safe for objects */
             $className = TypeHandling::getTypeForValue($subject);
             if (property_exists($className, $propertyName)) {
                 $propertyReflection = new \ReflectionProperty($className, $propertyName);
                 $propertyReflection->setAccessible(true);
                 $propertyReflection->setValue($subject, $propertyValue);
-            } elseif ($subject instanceof ProxyInterface && property_exists(get_parent_class($className), $propertyName)) {
-                $propertyReflection = new \ReflectionProperty(get_parent_class($className), $propertyName);
+            } elseif ($subject instanceof ProxyInterface && property_exists(get_parent_class($className) ?: $className, $propertyName)) {
+                $propertyReflection = new \ReflectionProperty(get_parent_class($className) ?: $className, $propertyName);
                 $propertyReflection->setAccessible(true);
                 $propertyReflection->setValue($subject, $propertyValue);
             } else {
@@ -290,19 +281,17 @@ public static function setProperty(&$subject, $propertyName, $propertyValue, boo
      * - public properties which can be directly get.
      *
      * @param object $object Object to receive property names for
-     * @return array Array of all gettable property names
+     * @return array<int,string> Array of all gettable property names
      * @throws \InvalidArgumentException
      */
-    public static function getGettablePropertyNames($object): array
+    public static function getGettablePropertyNames(object $object): array
     {
-        if (!is_object($object)) {
-            throw new \InvalidArgumentException('$object must be an object, ' . gettype($object) . ' given.', 1237301369);
-        }
         if ($object instanceof \stdClass) {
             $declaredPropertyNames = array_keys(get_object_vars($object));
             $className = 'stdClass';
             unset(self::$gettablePropertyNamesCache[$className]);
         } else {
+            /** @var string $className safe for objects */
             $className = TypeHandling::getTypeForValue($object);
             $declaredPropertyNames = array_keys(get_class_vars($className));
         }
@@ -336,17 +325,15 @@ public static function getGettablePropertyNames($object): array
      * - public properties which can be directly set.
      *
      * @param object $object Object to receive property names for
-     * @return array Array of all settable property names
+     * @return array<int,string> Array of all settable property names
      * @throws \InvalidArgumentException
      */
-    public static function getSettablePropertyNames($object): array
+    public static function getSettablePropertyNames(object $object): array
     {
-        if (!is_object($object)) {
-            throw new \InvalidArgumentException('$object must be an object, ' . gettype($object) . ' given.', 1264022994);
-        }
         if ($object instanceof \stdClass) {
             $declaredPropertyNames = array_keys(get_object_vars($object));
         } else {
+            /** @var string $className safe for object */
             $className = TypeHandling::getTypeForValue($object);
             $declaredPropertyNames = array_keys(get_class_vars($className));
         }
@@ -370,12 +357,9 @@ public static function getSettablePropertyNames($object): array
      * @return boolean
      * @throws \InvalidArgumentException
      */
-    public static function isPropertySettable($object, string $propertyName): bool
+    public static function isPropertySettable(object $object, string $propertyName): bool
     {
-        if (!is_object($object)) {
-            throw new \InvalidArgumentException('$object must be an object, ' . gettype($object) . ' given.', 1259828920);
-        }
-
+        /** @var string $className safe for objects */
         $className = TypeHandling::getTypeForValue($object);
         if (($object instanceof \stdClass && array_key_exists($propertyName, get_object_vars($object))) || array_key_exists($propertyName, get_class_vars($className))) {
             return true;
@@ -391,18 +375,19 @@ public static function isPropertySettable($object, string $propertyName): bool
      * @return boolean
      * @throws \InvalidArgumentException
      */
-    public static function isPropertyGettable($object, string $propertyName): bool
+    public static function isPropertyGettable(object $object, string $propertyName): bool
     {
-        if (!is_object($object)) {
-            throw new \InvalidArgumentException('$object must be an object, ' . gettype($object) . ' given.', 1259828921);
-        }
-        if (($object instanceof \ArrayAccess && $object->offsetExists($propertyName)) || ($object instanceof \stdClass && array_key_exists($propertyName, get_object_vars($object)))) {
+        if (
+            $object instanceof \ArrayAccess && $object->offsetExists($propertyName)
+            || $object instanceof \stdClass && array_key_exists($propertyName, get_object_vars($object))
+        ) {
             return true;
         }
         $uppercasePropertyName = ucfirst($propertyName);
         if (is_callable([$object, 'get' . $uppercasePropertyName]) || is_callable([$object, 'is' . $uppercasePropertyName]) || is_callable([$object, 'has' . $uppercasePropertyName])) {
             return true;
         }
+        /** @var string $className safe for objects */
         $className = TypeHandling::getTypeForValue($object);
         return array_key_exists($propertyName, get_class_vars($className));
     }
@@ -412,15 +397,11 @@ public static function isPropertyGettable($object, string $propertyName): bool
      * $object that are accessible through this class.
      *
      * @param object $object Object to get all properties from.
-     * @return array Associative array of all properties.
-     * @throws \InvalidArgumentException
+     * @return array<string,mixed> Associative array of all properties.
      * @todo What to do with ArrayAccess
      */
-    public static function getGettableProperties($object): array
+    public static function getGettableProperties(object $object): array
     {
-        if (!is_object($object)) {
-            throw new \InvalidArgumentException('$object must be an object, ' . gettype($object) . ' given.', 1237301370);
-        }
         $properties = [];
         foreach (self::getGettablePropertyNames($object) as $propertyName) {
             $propertyExists = false;
diff --git a/Neos.Utility.ObjectHandling/Classes/TypeHandling.php b/Neos.Utility.ObjectHandling/Classes/TypeHandling.php
index c078b86b71..f858586827 100644
--- a/Neos.Utility.ObjectHandling/Classes/TypeHandling.php
+++ b/Neos.Utility.ObjectHandling/Classes/TypeHandling.php
@@ -31,16 +31,16 @@ abstract class TypeHandling
     const LITERAL_TYPE_PATTERN = '/^(?:integer|int|float|double|boolean|bool|string)$/';
 
     /**
-     * @var array
+     * @var array<int,string|class-string<\Traversable<mixed>>>
      */
-    protected static $collectionTypes = ['array', \Traversable::class];
+    protected static array $collectionTypes = ['array', \Traversable::class];
 
     /**
      * Returns an array with type information, including element type for
      * collection types (array, SplObjectStorage, ...)
      *
      * @param string $type Type of the property (see PARSE_TYPE_PATTERN)
-     * @return array An array with information about the type
+     * @return array{type: string, elementType: ?string, nullable: bool} An array with information about the type
      * @throws InvalidTypeException
      */
     public static function parseType(string $type): array
@@ -52,7 +52,7 @@ public static function parseType(string $type): array
 
         $typeWithoutNull = self::stripNullableType($type);
         $isNullable = $typeWithoutNull !== $type || $type === 'null';
-        $type = self::normalizeType($matches['type']);
+        $type = self::normalizeType($matches['type'] ?? '');
         $elementType = isset($matches['elementType']) ? self::normalizeType($matches['elementType']) : null;
 
         if ($elementType !== null && !self::isCollectionType($type)) {
@@ -116,7 +116,7 @@ public static function isSimpleType(string $type): bool
     /**
      * Returns true if the $type is a collection type.
      *
-     * @param string $type
+     * @param string|class-string<object> $type
      * @return boolean
      */
     public static function isCollectionType(string $type): bool
@@ -127,8 +127,11 @@ public static function isCollectionType(string $type): bool
 
         if (class_exists($type) === true || interface_exists($type) === true) {
             foreach (self::$collectionTypes as $collectionType) {
-                if (is_subclass_of($type, $collectionType) === true) {
-                    return true;
+                if (class_exists($collectionType)) {
+                    /** @var class-string<\Traversable<mixed>> $collectionType */
+                    if (is_subclass_of($type, $collectionType) === true) {
+                        return true;
+                    }
                 }
             }
         }
@@ -185,21 +188,23 @@ public static function stripNullableType($type)
         if (stripos($type, 'null') === false) {
             return $type;
         }
-        return preg_replace('/(\\|null|null\\|)/i', '', $type);
+        return preg_replace('/(\\|null|null\\|)/i', '', $type) ?: '';
     }
 
     /**
      * Return simple type or class for object
      *
      * @param mixed $value
-     * @return string
+     * @return ($value is object ? class-string : ?string)
      */
-    public static function getTypeForValue($value): string
+    public static function getTypeForValue($value): ?string
     {
         if (is_object($value)) {
             if ($value instanceof Proxy) {
+                /** @var class-string $type */
                 $type = get_parent_class($value);
             } else {
+                /** @var class-string $type */
                 $type = get_class($value);
             }
         } else {
diff --git a/Neos.Utility.Pdo/Classes/PdoHelper.php b/Neos.Utility.Pdo/Classes/PdoHelper.php
index 873ef34621..40ac1dac76 100644
--- a/Neos.Utility.Pdo/Classes/PdoHelper.php
+++ b/Neos.Utility.Pdo/Classes/PdoHelper.php
@@ -33,7 +33,7 @@ abstract class PdoHelper
      * @param \PDO $databaseHandle
      * @param string $pdoDriver
      * @param string $pathAndFilename
-     * @param array $replacePairs every key in this array will be replaced with the corresponding value in the loaded SQL (example: ['###CACHE_TABLE_NAME###' => 'caches', '###TAGS_TABLE_NAME###' => 'tags'])
+     * @param array<string,string> $replacePairs every key in this array will be replaced with the corresponding value in the loaded SQL (example: ['###CACHE_TABLE_NAME###' => 'caches', '###TAGS_TABLE_NAME###' => 'tags'])
      * @return void
      */
     public static function importSql(\PDO $databaseHandle, string $pdoDriver, string $pathAndFilename, array $replacePairs = [])
@@ -46,13 +46,13 @@ public static function importSql(\PDO $databaseHandle, string $pdoDriver, string
         } else {
             $sql = file($pathAndFilename, FILE_IGNORE_NEW_LINES & FILE_SKIP_EMPTY_LINES);
             // Remove MySQL style key length delimiters (yuck!) if we are not setting up a MySQL db
-            if ($pdoDriver !== 'mysql') {
+            if ($sql !== false && $pdoDriver !== 'mysql') {
                 $sql = preg_replace('/"\([0-9]+\)/', '"', $sql);
             }
         }
 
         $statement = '';
-        foreach ($sql as $line) {
+        foreach ($sql ?: [] as $line) {
             $statement .= ' ' . trim(strtr($line, $replacePairs));
             if (substr($statement, -1) === ';') {
                 $databaseHandle->exec($statement);
diff --git a/Neos.Utility.Schema/Classes/SchemaGenerator.php b/Neos.Utility.Schema/Classes/SchemaGenerator.php
index 07a977c120..5ac82327d2 100644
--- a/Neos.Utility.Schema/Classes/SchemaGenerator.php
+++ b/Neos.Utility.Schema/Classes/SchemaGenerator.php
@@ -26,7 +26,7 @@ class SchemaGenerator
      * Generate a schema for the given value
      *
      * @param mixed $value value to create a schema for
-     * @return array schema as array structure
+     * @return array<string,mixed> schema as array structure
      */
     public function generate($value): array
     {
@@ -62,8 +62,8 @@ public function generate($value): array
     /**
      * Create a schema for a dictionary
      *
-     * @param array $dictionaryValue
-     * @return array
+     * @param array<mixed> $dictionaryValue
+     * @return array{type: string, properties: array<mixed>}
      */
     protected function generateDictionarySchema(array $dictionaryValue): array
     {
@@ -78,8 +78,8 @@ protected function generateDictionarySchema(array $dictionaryValue): array
     /**
      * Create a schema for an array structure
      *
-     * @param array $arrayValue
-     * @return array schema
+     * @param array<mixed> $arrayValue
+     * @return array<string,mixed> schema
      */
     protected function generateArraySchema(array $arrayValue): array
     {
@@ -96,7 +96,7 @@ protected function generateArraySchema(array $arrayValue): array
      * Create a schema for a given string
      *
      * @param string $stringValue
-     * @return array
+     * @return array<string,mixed>
      */
     protected function generateStringSchema(string $stringValue): array
     {
@@ -122,7 +122,7 @@ protected function generateStringSchema(string $stringValue): array
      * Compact an array of items to avoid adding the same value more than once.
      * If the result contains only one item, that item is returned directly.
      *
-     * @param array $values array of values
+     * @param array<mixed> $values array of values
      * @return mixed
      */
     protected function filterDuplicatesFromArray(array $values)
diff --git a/Neos.Utility.Schema/Classes/SchemaValidator.php b/Neos.Utility.Schema/Classes/SchemaValidator.php
index 64fec01df2..82427d9827 100644
--- a/Neos.Utility.Schema/Classes/SchemaValidator.php
+++ b/Neos.Utility.Schema/Classes/SchemaValidator.php
@@ -69,7 +69,7 @@ class SchemaValidator
      *
      * @param mixed $value value to validate
      * @param mixed $schema type as string, schema or array of schemas
-     * @param array $types the additional type schemas
+     * @param array<mixed> $types the additional type schemas
      * @return ErrorResult
      */
     public function validate($value, $schema, array $types = []): ErrorResult
@@ -147,8 +147,8 @@ public function validate($value, $schema, array $types = []): ErrorResult
      * Validate a value for a given type
      *
      * @param mixed $value
-     * @param array $schema
-     * @param array $types
+     * @param array<string,mixed> $schema
+     * @param array<mixed> $types
      * @return ErrorResult
      */
     protected function validateType($value, array $schema, array $types = []): ErrorResult
@@ -209,8 +209,8 @@ protected function validateType($value, array $schema, array $types = []): Error
      * Validate a value with a given list of allowed types
      *
      * @param mixed $value
-     * @param array $schema
-     * @param array $types
+     * @param array<string,mixed> $schema
+     * @param array<mixed> $types
      * @return ErrorResult
      */
     protected function validateTypeArray($value, array $schema, array $types = []): ErrorResult
@@ -254,7 +254,7 @@ protected function validateTypeArray($value, array $schema, array $types = []):
      * - divisibleBy : value is divisibleBy the given number
      *
      * @param mixed $value
-     * @param array $schema
+     * @param array<string,mixed> $schema
      * @return ErrorResult
      */
     protected function validateNumberType($value, array $schema): ErrorResult
@@ -305,7 +305,7 @@ protected function validateNumberType($value, array $schema): ErrorResult
      *
      * @see SchemaValidator::validateNumberType
      * @param mixed $value
-     * @param array $schema
+     * @param array<mixed> $schema
      * @return ErrorResult
      */
     protected function validateIntegerType($value, array $schema): ErrorResult
@@ -323,7 +323,7 @@ protected function validateIntegerType($value, array $schema): ErrorResult
      * Validate a boolean value with the given schema
      *
      * @param mixed $value
-     * @param array $schema
+     * @param array<mixed> $schema
      * @return ErrorResult
      */
     protected function validateBooleanType($value, array $schema): ErrorResult
@@ -346,8 +346,8 @@ protected function validateBooleanType($value, array $schema): ErrorResult
      * - uniqueItems : allow only unique values
      *
      * @param mixed $value
-     * @param array $schema
-     * @param array $types
+     * @param array<string,mixed> $schema
+     * @param array<mixed> $types
      * @return ErrorResult
      */
     protected function validateArrayType($value, array $schema, array $types = []): ErrorResult
@@ -404,8 +404,8 @@ protected function validateArrayType($value, array $schema, array $types = []):
      * - additionalProperties : if false is given all additionalProperties are forbidden, if a schema is given all additional properties have to match the schema
      *
      * @param mixed $value
-     * @param array $schema
-     * @param array $types
+     * @param array<int|string,mixed> $schema
+     * @param array<int|string,mixed> $types
      * @return ErrorResult
      */
     protected function validateDictionaryType($value, array $schema, array $types = []): ErrorResult
@@ -496,8 +496,8 @@ protected function validateDictionaryType($value, array $schema, array $types =
      *   [date-time|date|time|uri|email|ipv4|ipv6|ip-address|host-name|class-name|interface-name]
      *
      * @param mixed $value
-     * @param array $schema
-     * @param array $types
+     * @param array<string,mixed> $schema
+     * @param array<mixed> $types
      * @return ErrorResult
      */
     protected function validateStringType($value, array $schema, array $types = []): ErrorResult
@@ -530,6 +530,7 @@ protected function validateStringType($value, array $schema, array $types = []):
             switch ($schema['format']) {
                 case 'date-time':
                     // YYYY-MM-DDThh:mm:ssZ ISO8601
+                    /** @phpstan-ignore staticMethod.resultUnused (we only care about the error) */
                     \DateTime::createFromFormat(\DateTime::ISO8601, $value);
                     $parseErrors = \DateTime::getLastErrors();
                     if ($parseErrors && $parseErrors['error_count'] > 0) {
@@ -538,6 +539,7 @@ protected function validateStringType($value, array $schema, array $types = []):
                     break;
                 case 'date':
                     // YYYY-MM-DD
+                    /** @phpstan-ignore staticMethod.resultUnused (we only care about the error) */
                     \DateTime::createFromFormat('Y-m-d', $value);
                     $parseErrors = \DateTime::getLastErrors();
                     if ($parseErrors && $parseErrors['error_count'] > 0) {
@@ -546,6 +548,7 @@ protected function validateStringType($value, array $schema, array $types = []):
                     break;
                 case 'time':
                     // hh:mm:ss
+                    /** @phpstan-ignore staticMethod.resultUnused (we only care about the error) */
                     \DateTime::createFromFormat('H:i:s', $value);
                     $parseErrors = \DateTime::getLastErrors();
                     if ($parseErrors && $parseErrors['error_count'] > 0) {
@@ -604,7 +607,7 @@ protected function validateStringType($value, array $schema, array $types = []):
      * Validate a null value with the given schema
      *
      * @param mixed $value
-     * @param array $schema
+     * @param array<mixed> $schema
      * @return ErrorResult
      */
     protected function validateNullType($value, array $schema): ErrorResult
@@ -620,7 +623,7 @@ protected function validateNullType($value, array $schema): ErrorResult
      * Validate any value with the given schema. Return always a valid Result.
      *
      * @param mixed $value
-     * @param array $schema
+     * @param array<int|string,mixed> $schema
      * @return ErrorResult
      */
     protected function validateAnyType($value, array $schema): ErrorResult
@@ -665,7 +668,7 @@ protected function createError(string $expectation, $value = null): Error
      * Determine whether the given php array is a schema or not
      *
      * @todo there should be a more sophisticated way to detect schemas
-     * @param array $phpArray
+     * @param array<int|string, mixed> $phpArray
      * @return boolean
      */
     protected function isSchema(array $phpArray): bool
@@ -677,7 +680,7 @@ protected function isSchema(array $phpArray): bool
     /**
      * Determine whether the given php array is a plain numerically indexed array
      *
-     * @param array $phpArray
+     * @param array<int|string,mixed> $phpArray
      * @return boolean
      */
     protected function isNumericallyIndexedArray(array $phpArray): bool
@@ -693,7 +696,7 @@ protected function isNumericallyIndexedArray(array $phpArray): bool
     /**
      * Determine whether the given php array is a Dictionary (has no numeric identifiers)
      *
-     * @param array $phpArray
+     * @param array<int|string, mixed> $phpArray
      * @return boolean
      */
     protected function isDictionary(array $phpArray): bool
diff --git a/Neos.Utility.Unicode/Classes/Functions.php b/Neos.Utility.Unicode/Classes/Functions.php
index a13429ebb5..806227f83d 100644
--- a/Neos.Utility.Unicode/Classes/Functions.php
+++ b/Neos.Utility.Unicode/Classes/Functions.php
@@ -31,7 +31,7 @@ public static function strtotitle(string $string): string
     {
         $result = '';
         $splitIntoLowerCaseWords = preg_split("/([\n\r\t ])/", self::strtolower($string), -1, PREG_SPLIT_DELIM_CAPTURE);
-        foreach ($splitIntoLowerCaseWords as $delimiterOrValue) {
+        foreach ($splitIntoLowerCaseWords  ?: [] as $delimiterOrValue) {
             $result .= self::strtoupper(self::substr($delimiterOrValue, 0, 1)) . self::substr($delimiterOrValue, 1);
         }
         return $result;
@@ -133,7 +133,7 @@ public static function lcfirst(string $string): string
      * @param string $haystack UTF-8 string to search in
      * @param string $needle UTF-8 string to search for
      * @param integer $offset Positition to start the search
-     * @return integer The character position
+     * @return integer|false The character position
      * @api
      */
     public static function strpos(string $haystack, string $needle, int $offset = 0)
@@ -154,16 +154,19 @@ public static function strpos(string $haystack, string $needle, int $offset = 0)
      * @see http://www.php.net/manual/en/function.pathinfo.php
      *
      * @param string $path
-     * @param integer $options Optional, one of PATHINFO_DIRNAME, PATHINFO_BASENAME, PATHINFO_EXTENSION or PATHINFO_FILENAME.
-     * @return string|array
+     * @param integer|null $options Optional, one of PATHINFO_DIRNAME, PATHINFO_BASENAME, PATHINFO_EXTENSION or PATHINFO_FILENAME.
+     * @return ($options is null ? array{dirname: string, basename: string, extension: string, filename: string} : string)
      * @api
      */
-    public static function pathinfo(string $path, ?int $options = null)
+    public static function pathinfo(string $path, ?int $options = null): string|array
     {
+        /** @var string $currentLocale we assume the current locale to be properly set */
+        /** @phpstan-ignore argument.type (int is allowed for locales) */
         $currentLocale = setlocale(LC_CTYPE, 0);
         // Before we have a setting for setlocale, his should suffice for pathinfo
         // to work correctly on Unicode strings
         setlocale(LC_CTYPE, 'en_US.UTF-8');
+        /** @var string|array{dirname: string, basename: string, extension: string, filename: string} $pathinfo */
         $pathinfo = $options == null ? pathinfo($path) : pathinfo($path, $options);
         setlocale(LC_CTYPE, $currentLocale);
         return $pathinfo;
@@ -188,8 +191,11 @@ public static function parse_url(string $url, int $component = -1)
         $encodedUrl = preg_replace_callback('%[^:@/?#&=\.]+%usD', function ($matches) {
             return urlencode($matches[0]);
         }, $url);
-        $components = parse_url($encodedUrl);
+        if ($encodedUrl === null) {
+            return false;
+        }
 
+        $components = parse_url($encodedUrl);
         if ($components === false) {
             return false;
         }
diff --git a/Neos.Utility.Unicode/Classes/TextIterator.php b/Neos.Utility.Unicode/Classes/TextIterator.php
index 862a05c204..2af09dd48d 100644
--- a/Neos.Utility.Unicode/Classes/TextIterator.php
+++ b/Neos.Utility.Unicode/Classes/TextIterator.php
@@ -19,6 +19,7 @@
 /**
  * A UTF8-aware TextIterator
  *
+ * @implements \Iterator<int,string>
  */
 class TextIterator implements \Iterator
 {
@@ -68,12 +69,12 @@ class TextIterator implements \Iterator
     protected $currentPosition;
 
     /**
-     * @var \ArrayObject
+     * @var \ArrayObject<int,TextIteratorElement>
      */
     protected $iteratorCache;
 
     /**
-     * @var \ArrayIterator
+     * @var \ArrayIterator<int,TextIteratorElement>
      */
     protected $iteratorCacheIterator;
 
@@ -109,11 +110,11 @@ public function __construct(string $subject, int $iteratorType = self::CHARACTER
     /**
      * Returns the current element
      *
-     * @return string The value of the current element
+     * @return string|null The value of the current element
      */
-    public function current(): string
+    public function current(): ?string
     {
-        return $this->getCurrentElement()->getValue();
+        return $this->getCurrentElement()?->getValue();
     }
 
     /**
@@ -123,7 +124,7 @@ public function current(): string
      */
     public function next(): void
     {
-        $this->previousElement = $this->getCurrentElement();
+        $this->previousElement = $this->getCurrentElement() ?: $this->previousElement;
         $this->iteratorCacheIterator->next();
     }
 
@@ -164,11 +165,11 @@ public function rewind(): void
     /**
      * Returns the offset in the original given string of the current element
      *
-     * @return integer The offset of the current element
+     * @return int|null The offset of the current element, if any
      */
-    public function offset(): int
+    public function offset(): ?int
     {
-        return $this->getCurrentElement()->getOffset();
+        return $this->getCurrentElement()?->getOffset();
     }
 
     /**
@@ -194,7 +195,8 @@ public function last(): string
             $previousElement = $this->getCurrentElement();
             $this->next();
         }
-        return $previousElement->getValue();
+        // can never be null because the iterator cannot be empty
+        return $previousElement?->getValue() ?: '';
     }
 
     /**
@@ -202,15 +204,15 @@ public function last(): string
      * given by its offset
      *
      * @param integer $offset The offset of the character
-     * @return int The offset of the element following this character
+     * @return int|null The offset of the element following this character or null if the offset is out of bounds
      */
-    public function following(int $offset): int
+    public function following(int $offset): ?int
     {
         $this->rewind();
         while ($this->valid()) {
             $this->next();
             $nextElement = $this->getCurrentElement();
-            if ($nextElement->getOffset() >= $offset) {
+            if ($nextElement && $nextElement->getOffset() >= $offset) {
                 return $nextElement->getOffset();
             }
         }
@@ -231,7 +233,7 @@ public function preceding(int $offset): int
             $previousElement = $this->getCurrentElement();
             $this->next();
             $currentElement = $this->getCurrentElement();
-            if (($currentElement->getOffset() + $currentElement->getLength()) >= $offset) {
+            if ($previousElement && $currentElement && ($currentElement->getOffset() + $currentElement->getLength()) >= $offset) {
                 return $previousElement->getOffset() + $previousElement->getLength();
             }
         }
@@ -254,20 +256,21 @@ public function preceding(int $offset): int
      */
     public function isBoundary(): bool
     {
-        return $this->getCurrentElement()->isBoundary();
+        return $this->getCurrentElement()?->isBoundary() ?: false;
     }
 
     /**
      * Returns all elements of the iterator in an array
      *
-     * @return array All elements of the iterator
+     * @return array<int,string> All elements of the iterator
      */
     public function getAll(): array
     {
         $this->rewind();
         $allValues = [];
         while ($this->valid()) {
-            $allValues[] = $this->getCurrentElement()->getValue();
+            // will never be null while valid
+            $allValues[] = $this->getCurrentElement()?->getValue() ?: '';
             $this->next();
         }
         return $allValues;
@@ -276,7 +279,7 @@ public function getAll(): array
     /**
      * @throws UnsupportedFeatureException
      */
-    public function getRuleStatus()
+    public function getRuleStatus(): never
     {
         throw new UnsupportedFeatureException('getRuleStatus() is not supported.', 1210849057);
     }
@@ -284,7 +287,7 @@ public function getRuleStatus()
     /**
      * @throws UnsupportedFeatureException
      */
-    public function getRuleStatusArray()
+    public function getRuleStatusArray(): never
     {
         throw new UnsupportedFeatureException('getRuleStatusArray() is not supported.', 1210849076);
     }
@@ -292,7 +295,7 @@ public function getRuleStatusArray()
     /**
      * @throws UnsupportedFeatureException
      */
-    public function getAvailableLocales()
+    public function getAvailableLocales(): never
     {
         throw new UnsupportedFeatureException('getAvailableLocales() is not supported.', 1210849105);
     }
@@ -305,7 +308,8 @@ public function getAvailableLocales()
     public function first(): string
     {
         $this->rewind();
-        return $this->getCurrentElement()->getValue();
+        // can never be empty, will at least contain empty string
+        return $this->getCurrentElement()?->getValue() ?: '';
     }
 
     /**
@@ -346,7 +350,7 @@ private function generateIteratorElements()
     private function parseSubjectByCharacter(): void
     {
         $i = 0;
-        foreach (preg_split('//u', $this->subject) as $currentCharacter) {
+        foreach (preg_split('//u', $this->subject) ?: [] as $currentCharacter) {
             if ($currentCharacter === '') {
                 continue;
             }
@@ -373,7 +377,7 @@ private function parseSubjectByWord()
                 $this->iteratorCache->append(new TextIteratorElement(' ', $i, 1, true));
 
                 $j = 0;
-                $splittedWord = preg_split('/' . self::REGEXP_SENTENCE_DELIMITERS . '/', $currentWord);
+                $splittedWord = preg_split('/' . self::REGEXP_SENTENCE_DELIMITERS . '/', $currentWord) ?: [];
                 foreach ($splittedWord as $currentPart) {
                     if ($currentPart !== '') {
                         $this->iteratorCache->append(new TextIteratorElement($currentPart, $i, Unicode\Functions::strlen($currentPart), false));
@@ -442,7 +446,7 @@ private function parseSubjectBySentence()
         $count = 0;
         $delimitersMatches = [];
         preg_match_all('/' . self::REGEXP_SENTENCE_DELIMITERS . '/', $this->subject, $delimitersMatches);
-        $splittedSentence = preg_split('/' . self::REGEXP_SENTENCE_DELIMITERS . '/', $this->subject);
+        $splittedSentence = preg_split('/' . self::REGEXP_SENTENCE_DELIMITERS . '/', $this->subject) ?: [];
 
         if (count($splittedSentence) == 1) {
             $this->iteratorCache->append(new TextIteratorElement($splittedSentence[0], 0, Unicode\Functions::strlen($splittedSentence[0]), false));
@@ -480,6 +484,7 @@ private function parseSubjectBySentence()
      * Helper function to get the current element from the cache.
      *
      * @return TextIteratorElement|null The current element of the cache
+     * @phpstan-ignore return.unusedType (can be null if next() leaves the valid range of the iterator)
      */
     private function getCurrentElement()
     {
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index 9b730bf93b..357d31969e 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -1,5 +1,5 @@
 parameters:
-    level: 3
+    level: 8
     paths:
         - Neos.Cache/Classes
         - Neos.Eel/Classes