diff --git a/exercises/practice/bank-account/BankAccountTests.cs b/exercises/practice/bank-account/BankAccountTests.cs
index 1e8890929..50d6b66cc 100644
--- a/exercises/practice/bank-account/BankAccountTests.cs
+++ b/exercises/practice/bank-account/BankAccountTests.cs
@@ -162,7 +162,7 @@ public async Task Can_handle_concurrent_transactions()
                     account.Deposit(1m);
                     account.Withdraw(1m);
                 }
-            }));
+            }, TestContext.Current.CancellationToken));
             await Task.WhenAll(tasks.ToArray());
         }
         Assert.Equal(0m, account.Balance);
diff --git a/exercises/practice/ledger/.meta/Example.cs b/exercises/practice/ledger/.meta/Example.cs
index 347b7ac25..e77240ffe 100644
--- a/exercises/practice/ledger/.meta/Example.cs
+++ b/exercises/practice/ledger/.meta/Example.cs
@@ -1,18 +1,6 @@
 using System.Globalization;
 
-public class LedgerEntry
-{
-    public LedgerEntry(DateTime date, string description, decimal change)
-    {
-        Date = date;
-        Description = description;
-        Change = change;
-    }
-
-    public DateTime Date { get; }
-    public string Description { get; }
-    public decimal Change { get; }
-}
+public record LedgerEntry(DateTime Date, string Description, decimal Change);
 
 public static class Ledger
 {
@@ -20,51 +8,43 @@ public static class Ledger
     private const string TruncateSuffix = "...";
 
     public static LedgerEntry CreateEntry(string date, string description, int change) =>
-        new LedgerEntry(ParseDate(date), description, ParseChange(change));
+        new(ParseDate(date), description, ParseChange(change));
 
     private static DateTime ParseDate(string date) => DateTime.Parse(date, System.Globalization.CultureInfo.InvariantCulture);
 
     private static decimal ParseChange(int change) => change / 100.0m;
 
-    private static CultureInfo CultureInfo(string locale)
-    {
-        switch (locale)
+    private static CultureInfo CultureInfo(string locale) =>
+        locale switch
         {
-            case "en-US": return new CultureInfo("en-US", false);
-            case "nl-NL": return new CultureInfo("nl-NL", false);
-            default: throw new ArgumentException("Invalid locale");
-        }
-    }
+            "en-US" => new CultureInfo("en-US", false),
+            "nl-NL" => new CultureInfo("nl-NL", false),
+            _ => throw new ArgumentException("Invalid locale")
+        };
 
-    private static string CurrencySymbol(string currency)
-    {
-        switch (currency)
+    private static string CurrencySymbol(string currency) =>
+        currency switch
         {
-            case "USD": return "$";
-            case "EUR": return "€";
-            default: throw new ArgumentException("Invalid currency");
-        }
-    }
+            "USD" => "$",
+            "EUR" => "€",
+            _ => throw new ArgumentException("Invalid currency")
+        };
 
-    private static int CurrencyNegativePattern(string locale)
-    {
-        switch (locale)
+    private static int CurrencyNegativePattern(string locale) =>
+        locale switch
         {
-            case "en-US": return 0;
-            case "nl-NL": return 12;
-            default: throw new ArgumentException("Invalid locale");
-        }
-    }
+            "en-US" => 0,
+            "nl-NL" => 12,
+            _ => throw new ArgumentException("Invalid locale")
+        };
 
-    private static string ShortDateFormat(string locale)
-    {
-        switch (locale)
+    private static string ShortDateFormat(string locale) =>
+        locale switch
         {
-            case "en-US": return "MM/dd/yyyy";
-            case "nl-NL": return "dd/MM/yyyy";
-            default: throw new ArgumentException("Invalid locale");
-        }
-    }
+            "en-US" => "MM/dd/yyyy",
+            "nl-NL" => "dd/MM/yyyy",
+            _ => throw new ArgumentException("Invalid locale")
+        };
 
     private static CultureInfo getCulture(string currency, string locale)
     {
@@ -75,15 +55,13 @@ private static CultureInfo getCulture(string currency, string locale)
         return culture;
     }
 
-    private static string FormatHeader(CultureInfo culture)
-    {
-        switch (culture.Name)
+    private static string FormatHeader(CultureInfo culture) =>
+        culture.Name switch
         {
-            case "en-US": return "Date       | Description               | Change       ";
-            case "nl-NL": return "Datum      | Omschrijving              | Verandering  ";
-            default: throw new ArgumentException("Invalid locale");
-        }
-    }
+            "en-US" => "Date       | Description               | Change       ",
+            "nl-NL" => "Datum      | Omschrijving              | Verandering  ",
+            _ => throw new ArgumentException("Invalid locale")
+        };
 
     private static string FormatDate(IFormatProvider culture, DateTime date) => date.ToString("d", culture);
 
diff --git a/exercises/practice/ledger/Ledger.cs b/exercises/practice/ledger/Ledger.cs
index 4305db76f..247543085 100644
--- a/exercises/practice/ledger/Ledger.cs
+++ b/exercises/practice/ledger/Ledger.cs
@@ -23,9 +23,9 @@ public static LedgerEntry CreateEntry(string date, string desc, int chng)
 
     private static CultureInfo CreateCulture(string cur, string loc)
     {
-        string curSymb = null;
+        string? curSymb = null;
         int curNeg = 0;
-        string datPat = null;
+        string? datPat = null;
 
         if (cur != "USD" && cur != "EUR")
         {
@@ -70,9 +70,9 @@ private static CultureInfo CreateCulture(string cur, string loc)
         }
 
         var culture = new CultureInfo(loc, false);
-        culture.NumberFormat.CurrencySymbol = curSymb;
+        culture.NumberFormat.CurrencySymbol = curSymb!;
         culture.NumberFormat.CurrencyNegativePattern = curNeg;
-        culture.DateTimeFormat.ShortDatePattern = datPat;
+        culture.DateTimeFormat.ShortDatePattern = datPat!;
         return culture;
     }
 
diff --git a/exercises/practice/markdown/.meta/Example.cs b/exercises/practice/markdown/.meta/Example.cs
index 40e2bdb97..1a9d6eef7 100644
--- a/exercises/practice/markdown/.meta/Example.cs
+++ b/exercises/practice/markdown/.meta/Example.cs
@@ -5,7 +5,6 @@ public static class Markdown
     private static string OpeningTag(string tag) => $"<{tag}>";
     private static string ClosingTag(string tag) => $"</{tag}>";
     private static string WrapInTag(this string text, string tag) => $"{OpeningTag(tag)}{text}{ClosingTag(tag)}";
-    private static bool StartsWithTag(this string text, string tag) => text.StartsWith(OpeningTag(tag));
 
     private const string HeaderMarkdown = "#";
     private const string BoldMarkdown = "__";
diff --git a/exercises/practice/markdown/Markdown.cs b/exercises/practice/markdown/Markdown.cs
index f56520bd2..78707e9c2 100644
--- a/exercises/practice/markdown/Markdown.cs
+++ b/exercises/practice/markdown/Markdown.cs
@@ -31,7 +31,7 @@ private static string ParseText(string markdown, bool list)
         }
     }
 
-    private static string ParseHeader(string markdown, bool list, out bool inListAfter)
+    private static string? ParseHeader(string markdown, bool list, out bool inListAfter)
     {
         var count = 0;
 
@@ -68,7 +68,7 @@ private static string ParseHeader(string markdown, bool list, out bool inListAft
         }
     }
 
-    private static string ParseLineItem(string markdown, bool list, out bool inListAfter)
+    private static string? ParseLineItem(string markdown, bool list, out bool inListAfter)
     {
         if (markdown.StartsWith("*"))
         {