diff --git a/packages/core/src/awsService/appBuilder/explorer/nodes/deployedNode.ts b/packages/core/src/awsService/appBuilder/explorer/nodes/deployedNode.ts
index 24fa77939f3..d24e07e06da 100644
--- a/packages/core/src/awsService/appBuilder/explorer/nodes/deployedNode.ts
+++ b/packages/core/src/awsService/appBuilder/explorer/nodes/deployedNode.ts
@@ -13,7 +13,7 @@ import { getLogger } from '../../../../shared/logger/logger'
 import { DefaultLambdaClient } from '../../../../shared/clients/lambdaClient'
 import globals from '../../../../shared/extensionGlobals'
 import { defaultPartition } from '../../../../shared/regions/regionProvider'
-import { Lambda } from 'aws-sdk'
+import { FunctionConfiguration } from '@aws-sdk/client-lambda'
 import { RestApi } from '@aws-sdk/client-api-gateway'
 import { LambdaNode } from '../../../../lambda/explorer/lambdaNodes'
 import { LambdaFunctionNode } from '../../../../lambda/explorer/lambdaFunctionNode'
@@ -89,10 +89,10 @@ export async function generateDeployedNode(
             case SERVERLESS_FUNCTION_TYPE: {
                 const defaultClient = new DefaultLambdaClient(regionCode)
                 const lambdaNode = new LambdaNode(regionCode, defaultClient)
-                let configuration: Lambda.FunctionConfiguration
+                let configuration: FunctionConfiguration
                 try {
                     configuration = (await defaultClient.getFunction(deployedResource.PhysicalResourceId))
-                        .Configuration as Lambda.FunctionConfiguration
+                        .Configuration as FunctionConfiguration
                     newDeployedResource = new LambdaFunctionNode(
                         lambdaNode,
                         regionCode,
diff --git a/packages/core/src/awsService/appBuilder/explorer/samProject.ts b/packages/core/src/awsService/appBuilder/explorer/samProject.ts
index 722ec323192..faba9bcad76 100644
--- a/packages/core/src/awsService/appBuilder/explorer/samProject.ts
+++ b/packages/core/src/awsService/appBuilder/explorer/samProject.ts
@@ -9,6 +9,7 @@ import { SamConfig, SamConfigErrorCode } from '../../../shared/sam/config'
 import { getLogger } from '../../../shared/logger/logger'
 import { ToolkitError } from '../../../shared/errors'
 import { showViewLogsMessage } from '../../../shared/utilities/messages'
+import { Runtime } from '@aws-sdk/client-lambda'
 
 export interface SamApp {
     location: SamAppLocation
@@ -24,7 +25,7 @@ export interface SamAppLocation {
 export interface ResourceTreeEntity {
     Id: string
     Type: string
-    Runtime?: string
+    Runtime?: Runtime
     CodeUri?: string
     Handler?: string
     Events?: ResourceTreeEntity[]
diff --git a/packages/core/src/awsService/appBuilder/lambda2sam/lambda2sam.ts b/packages/core/src/awsService/appBuilder/lambda2sam/lambda2sam.ts
index 20f7c372583..75722842bc5 100644
--- a/packages/core/src/awsService/appBuilder/lambda2sam/lambda2sam.ts
+++ b/packages/core/src/awsService/appBuilder/lambda2sam/lambda2sam.ts
@@ -26,7 +26,7 @@ import {
 import { downloadUnzip, getLambdaClient, getCFNClient, isPermissionError } from '../utils'
 import { openProjectInWorkspace } from '../walkthrough'
 import { ToolkitError } from '../../../shared/errors'
-import { ResourcesToImport, StackResource } from 'aws-sdk/clients/cloudformation'
+import { ResourceToImport, StackResource } from '@aws-sdk/client-cloudformation'
 import { SignatureV4 } from '@smithy/signature-v4'
 import { Sha256 } from '@aws-crypto/sha256-js'
 import { getIAMConnection } from '../../../auth/utils'
@@ -79,7 +79,7 @@ export async function lambdaToSam(lambdaNode: LambdaFunctionNode): Promise<void>
                     progress.report({ increment: 30, message: 'Generating template...' })
                     // 2.1 call api to get CFN
                     let cfnTemplate: Template
-                    let resourcesToImport: ResourcesToImport
+                    let resourcesToImport: ResourceToImport[]
                     try {
                         ;[cfnTemplate, resourcesToImport] = await callExternalApiForCfnTemplate(lambdaNode)
                     } catch (error) {
@@ -282,7 +282,7 @@ export function ifSamTemplate(template: Template): boolean {
  */
 export async function callExternalApiForCfnTemplate(
     lambdaNode: LambdaFunctionNode
-): Promise<[Template, ResourcesToImport]> {
+): Promise<[Template, ResourceToImport[]]> {
     const conn = await getIAMConnection()
     if (!conn || conn.type !== 'iam') {
         return [{}, []]
@@ -333,7 +333,7 @@ export async function callExternalApiForCfnTemplate(
 
     let status: string | undefined = 'CREATE_IN_PROGRESS'
     let getGeneratedTemplateResponse
-    let resourcesToImport: ResourcesToImport = []
+    let resourcesToImport: ResourceToImport[] = []
     const cfn = await getCFNClient(lambdaNode.regionCode)
 
     // Wait for template generation to complete
@@ -438,7 +438,7 @@ async function promptForProjectLocation(): Promise<vscode.Uri[] | undefined> {
  */
 export async function deployCfnTemplate(
     template: Template,
-    resourcesToImport: ResourcesToImport,
+    resourcesToImport: ResourceToImport[],
     stackName: string,
     region: string
 ): Promise<StackInfo> {
@@ -901,13 +901,13 @@ export async function getPhysicalIdfromCFNResourceName(
 
         // Find resources that start with the given name (SAM transform often adds suffixes)
         const matchingResources = resources.StackResources.filter((resource: StackResource) =>
-            resource.LogicalResourceId.startsWith(name)
+            resource.LogicalResourceId?.startsWith(name)
         )
 
         if (matchingResources.length === 0) {
             // Try a more flexible approach - check if the resource name is a substring
             const substringMatches = resources.StackResources.filter((resource: StackResource) =>
-                resource.LogicalResourceId.includes(name)
+                resource.LogicalResourceId?.includes(name)
             )
 
             if (substringMatches.length === 0) {
@@ -926,7 +926,8 @@ export async function getPhysicalIdfromCFNResourceName(
         // If we have multiple matches, prefer exact prefix match
         // Sort by length to get the closest match (shortest additional suffix)
         matchingResources.sort(
-            (a: StackResource, b: StackResource) => a.LogicalResourceId.length - b.LogicalResourceId.length
+            (a: StackResource, b: StackResource) =>
+                (a.LogicalResourceId?.length ?? 0) - (b.LogicalResourceId?.length ?? 0)
         )
 
         const bestMatch = matchingResources[0]
diff --git a/packages/core/src/awsService/appBuilder/utils.ts b/packages/core/src/awsService/appBuilder/utils.ts
index bdaa6293b30..d88aa170f57 100644
--- a/packages/core/src/awsService/appBuilder/utils.ts
+++ b/packages/core/src/awsService/appBuilder/utils.ts
@@ -21,8 +21,51 @@ import { RuntimeFamily, getFamily } from '../../lambda/models/samLambdaRuntime'
 import { showMessage } from '../../shared/utilities/messages'
 import { DefaultLambdaClient } from '../../shared/clients/lambdaClient'
 import AdmZip from 'adm-zip'
-import { CloudFormation, Lambda } from 'aws-sdk'
+import {
+    CloudFormationClient,
+    CreateChangeSetCommand,
+    CreateChangeSetInput,
+    CreateChangeSetOutput,
+    DescribeChangeSetCommand,
+    DescribeChangeSetInput,
+    DescribeChangeSetOutput,
+    DescribeGeneratedTemplateCommand,
+    DescribeGeneratedTemplateInput,
+    DescribeGeneratedTemplateOutput,
+    DescribeStackResourceCommand,
+    DescribeStackResourceInput,
+    DescribeStackResourceOutput,
+    DescribeStackResourcesCommand,
+    DescribeStackResourcesInput,
+    DescribeStackResourcesOutput,
+    DescribeStacksCommand,
+    DescribeStacksInput,
+    DescribeStacksOutput,
+    ExecuteChangeSetCommand,
+    ExecuteChangeSetInput,
+    ExecuteChangeSetOutput,
+    GetGeneratedTemplateCommand,
+    GetGeneratedTemplateInput,
+    GetGeneratedTemplateOutput,
+    GetTemplateCommand,
+    GetTemplateInput,
+    GetTemplateOutput,
+    waitUntilChangeSetCreateComplete,
+    waitUntilStackImportComplete,
+    waitUntilStackUpdateComplete,
+} from '@aws-sdk/client-cloudformation'
+import {
+    FunctionConfiguration,
+    FunctionUrlConfig,
+    GetFunctionResponse,
+    GetLayerVersionResponse,
+    InvocationRequest,
+    InvocationResponse,
+    LayerVersionsListItem,
+    Runtime,
+} from '@aws-sdk/client-lambda'
 import { isAwsError, UnknownError } from '../../shared/errors'
+import { WaiterConfiguration } from '@aws-sdk/types'
 const localize = nls.loadMessageBundle()
 
 /**
@@ -230,7 +273,7 @@ export class EnhancedLambdaClient {
         }
     }
 
-    async invoke(name: string, payload?: Lambda.InvocationRequest['Payload']): Promise<Lambda.InvocationResponse> {
+    async invoke(name: string, payload?: InvocationRequest['Payload']): Promise<InvocationResponse> {
         try {
             return await this.client.invoke(name, payload)
         } catch (error) {
@@ -246,7 +289,7 @@ export class EnhancedLambdaClient {
         }
     }
 
-    async *listFunctions(): AsyncIterableIterator<Lambda.FunctionConfiguration> {
+    async *listFunctions(): AsyncIterableIterator<FunctionConfiguration> {
         try {
             yield* this.client.listFunctions()
         } catch (error) {
@@ -257,7 +300,7 @@ export class EnhancedLambdaClient {
         }
     }
 
-    async getFunction(name: string): Promise<Lambda.GetFunctionResponse> {
+    async getFunction(name: string): Promise<GetFunctionResponse> {
         try {
             return await this.client.getFunction(name)
         } catch (error) {
@@ -273,7 +316,7 @@ export class EnhancedLambdaClient {
         }
     }
 
-    async getLayerVersion(name: string, version: number): Promise<Lambda.GetLayerVersionResponse> {
+    async getLayerVersion(name: string, version: number): Promise<GetLayerVersionResponse> {
         try {
             return await this.client.getLayerVersion(name, version)
         } catch (error) {
@@ -289,7 +332,7 @@ export class EnhancedLambdaClient {
         }
     }
 
-    async *listLayerVersions(name: string): AsyncIterableIterator<Lambda.LayerVersionsListItem> {
+    async *listLayerVersions(name: string): AsyncIterableIterator<LayerVersionsListItem> {
         try {
             yield* this.client.listLayerVersions(name)
         } catch (error) {
@@ -305,7 +348,7 @@ export class EnhancedLambdaClient {
         }
     }
 
-    async getFunctionUrlConfigs(name: string): Promise<Lambda.FunctionUrlConfigList> {
+    async getFunctionUrlConfigs(name: string): Promise<FunctionUrlConfig[]> {
         try {
             return await this.client.getFunctionUrlConfigs(name)
         } catch (error) {
@@ -321,7 +364,7 @@ export class EnhancedLambdaClient {
         }
     }
 
-    async updateFunctionCode(name: string, zipFile: Uint8Array): Promise<Lambda.FunctionConfiguration> {
+    async updateFunctionCode(name: string, zipFile: Uint8Array): Promise<FunctionConfiguration> {
         try {
             return await this.client.updateFunctionCode(name, zipFile)
         } catch (error) {
@@ -343,13 +386,13 @@ export class EnhancedLambdaClient {
  */
 export class EnhancedCloudFormationClient {
     constructor(
-        private readonly client: CloudFormation,
+        private readonly client: CloudFormationClient,
         private readonly regionCode: string
     ) {}
 
-    async describeStacks(params: CloudFormation.DescribeStacksInput): Promise<CloudFormation.DescribeStacksOutput> {
+    async describeStacks(params: DescribeStacksInput): Promise<DescribeStacksOutput> {
         try {
-            return await this.client.describeStacks(params).promise()
+            return await this.client.send(new DescribeStacksCommand(params))
         } catch (error) {
             if (isPermissionError(error)) {
                 const stackArn = params.StackName
@@ -361,9 +404,9 @@ export class EnhancedCloudFormationClient {
         }
     }
 
-    async getTemplate(params: CloudFormation.GetTemplateInput): Promise<CloudFormation.GetTemplateOutput> {
+    async getTemplate(params: GetTemplateInput): Promise<GetTemplateOutput> {
         try {
-            return await this.client.getTemplate(params).promise()
+            return await this.client.send(new GetTemplateCommand(params))
         } catch (error) {
             if (isPermissionError(error)) {
                 const stackArn = params.StackName
@@ -375,9 +418,9 @@ export class EnhancedCloudFormationClient {
         }
     }
 
-    async createChangeSet(params: CloudFormation.CreateChangeSetInput): Promise<CloudFormation.CreateChangeSetOutput> {
+    async createChangeSet(params: CreateChangeSetInput): Promise<CreateChangeSetOutput> {
         try {
-            return await this.client.createChangeSet(params).promise()
+            return await this.client.send(new CreateChangeSetCommand(params))
         } catch (error) {
             if (isPermissionError(error)) {
                 const stackArn = params.StackName
@@ -389,11 +432,9 @@ export class EnhancedCloudFormationClient {
         }
     }
 
-    async executeChangeSet(
-        params: CloudFormation.ExecuteChangeSetInput
-    ): Promise<CloudFormation.ExecuteChangeSetOutput> {
+    async executeChangeSet(params: ExecuteChangeSetInput): Promise<ExecuteChangeSetOutput> {
         try {
-            return await this.client.executeChangeSet(params).promise()
+            return await this.client.send(new ExecuteChangeSetCommand(params))
         } catch (error) {
             if (isPermissionError(error)) {
                 const stackArn = params.StackName
@@ -405,11 +446,9 @@ export class EnhancedCloudFormationClient {
         }
     }
 
-    async describeChangeSet(
-        params: CloudFormation.DescribeChangeSetInput
-    ): Promise<CloudFormation.DescribeChangeSetOutput> {
+    async describeChangeSet(params: DescribeChangeSetInput): Promise<DescribeChangeSetOutput> {
         try {
-            return await this.client.describeChangeSet(params).promise()
+            return await this.client.send(new DescribeChangeSetCommand(params))
         } catch (error) {
             if (isPermissionError(error)) {
                 const stackArn = params.StackName
@@ -421,11 +460,9 @@ export class EnhancedCloudFormationClient {
         }
     }
 
-    async describeStackResources(
-        params: CloudFormation.DescribeStackResourcesInput
-    ): Promise<CloudFormation.DescribeStackResourcesOutput> {
+    async describeStackResources(params: DescribeStackResourcesInput): Promise<DescribeStackResourcesOutput> {
         try {
-            return await this.client.describeStackResources(params).promise()
+            return await this.client.send(new DescribeStackResourcesCommand(params))
         } catch (error) {
             if (isPermissionError(error)) {
                 const stackArn = params.StackName
@@ -437,11 +474,9 @@ export class EnhancedCloudFormationClient {
         }
     }
 
-    async describeStackResource(
-        params: CloudFormation.DescribeStackResourceInput
-    ): Promise<CloudFormation.DescribeStackResourceOutput> {
+    async describeStackResource(params: DescribeStackResourceInput): Promise<DescribeStackResourceOutput> {
         try {
-            return await this.client.describeStackResource(params).promise()
+            return await this.client.send(new DescribeStackResourceCommand(params))
         } catch (error) {
             if (isPermissionError(error)) {
                 const stackArn = params.StackName
@@ -453,11 +488,9 @@ export class EnhancedCloudFormationClient {
         }
     }
 
-    async getGeneratedTemplate(
-        params: CloudFormation.GetGeneratedTemplateInput
-    ): Promise<CloudFormation.GetGeneratedTemplateOutput> {
+    async getGeneratedTemplate(params: GetGeneratedTemplateInput): Promise<GetGeneratedTemplateOutput> {
         try {
-            return await this.client.getGeneratedTemplate(params).promise()
+            return await this.client.send(new GetGeneratedTemplateCommand(params))
         } catch (error) {
             if (isPermissionError(error)) {
                 throw createEnhancedPermissionError(error, 'cloudformation', 'getGeneratedTemplate')
@@ -466,11 +499,9 @@ export class EnhancedCloudFormationClient {
         }
     }
 
-    async describeGeneratedTemplate(
-        params: CloudFormation.DescribeGeneratedTemplateInput
-    ): Promise<CloudFormation.DescribeGeneratedTemplateOutput> {
+    async describeGeneratedTemplate(params: DescribeGeneratedTemplateInput): Promise<DescribeGeneratedTemplateOutput> {
         try {
-            return await this.client.describeGeneratedTemplate(params).promise()
+            return await this.client.send(new DescribeGeneratedTemplateCommand(params))
         } catch (error) {
             if (isPermissionError(error)) {
                 throw createEnhancedPermissionError(error, 'cloudformation', 'describeGeneratedTemplate')
@@ -481,7 +512,20 @@ export class EnhancedCloudFormationClient {
 
     async waitFor(state: string, params: any): Promise<any> {
         try {
-            return await this.client.waitFor(state as any, params).promise()
+            const waiterConfig = {
+                client: this.client,
+                maxWaitTime: 900,
+            } satisfies WaiterConfiguration<CloudFormationClient>
+            switch (state) {
+                case 'changeSetCreateComplete':
+                    return await waitUntilChangeSetCreateComplete(waiterConfig, params)
+                case 'stackImportComplete':
+                    return await waitUntilStackImportComplete(waiterConfig, params)
+                case 'stackUpdateComplete':
+                    return await waitUntilStackUpdateComplete(waiterConfig, params)
+                default:
+                    throw new Error(`Unsupported waiter state: ${state}`)
+            }
         } catch (error) {
             if (isPermissionError(error)) {
                 // For waitFor operations, we'll provide a generic permission error since the specific action varies
@@ -560,7 +604,7 @@ export async function getLambdaHandlerFile(
     folderUri: vscode.Uri,
     codeUri: string,
     handler: string,
-    runtime: string
+    runtime: Runtime
 ): Promise<vscode.Uri | undefined> {
     const family = getFamily(runtime)
     if (!supportedRuntimeForHandler.has(family)) {
@@ -704,6 +748,9 @@ export function getLambdaClient(region: string): EnhancedLambdaClient {
 }
 
 export async function getCFNClient(regionCode: string): Promise<EnhancedCloudFormationClient> {
-    const originalClient = await globals.sdkClientBuilder.createAwsService(CloudFormation, {}, regionCode)
+    const originalClient = globals.sdkClientBuilderV3.createAwsService({
+        serviceClient: CloudFormationClient,
+        region: regionCode,
+    })
     return new EnhancedCloudFormationClient(originalClient, regionCode)
 }
diff --git a/packages/core/src/eventSchemas/models/schemaCodeLangs.ts b/packages/core/src/eventSchemas/models/schemaCodeLangs.ts
index c2bec2e29f6..fe83459251a 100644
--- a/packages/core/src/eventSchemas/models/schemaCodeLangs.ts
+++ b/packages/core/src/eventSchemas/models/schemaCodeLangs.ts
@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { Runtime } from 'aws-sdk/clients/lambda'
+import { Runtime } from '@aws-sdk/client-lambda'
 import { Set as ImmutableSet } from 'immutable'
 import { goRuntimes } from '../../lambda/models/samLambdaRuntime'
 
diff --git a/packages/core/src/lambda/activation.ts b/packages/core/src/lambda/activation.ts
index eaebc17de3b..0b3224c2649 100644
--- a/packages/core/src/lambda/activation.ts
+++ b/packages/core/src/lambda/activation.ts
@@ -7,7 +7,7 @@ import * as path from 'path'
 import * as vscode from 'vscode'
 import * as nls from 'vscode-nls'
 
-import { Lambda } from 'aws-sdk'
+import { FunctionConfiguration } from '@aws-sdk/client-lambda'
 import { deleteLambda } from './commands/deleteLambda'
 import { uploadLambdaCommand } from './commands/uploadLambda'
 import { LambdaFunctionNode } from './explorer/lambdaFunctionNode'
@@ -229,7 +229,7 @@ export async function activate(context: ExtContext): Promise<void> {
         ),
 
         Commands.register('aws.appBuilder.tailLogs', async (node: LambdaFunctionNode | TreeNode) => {
-            let functionConfiguration: Lambda.FunctionConfiguration
+            let functionConfiguration: FunctionConfiguration
             try {
                 const sourceNode = getSourceNode<LambdaFunctionNode>(node)
                 functionConfiguration = sourceNode.configuration
diff --git a/packages/core/src/lambda/commands/copyLambdaUrl.ts b/packages/core/src/lambda/commands/copyLambdaUrl.ts
index d15a96a7d62..835525d0610 100644
--- a/packages/core/src/lambda/commands/copyLambdaUrl.ts
+++ b/packages/core/src/lambda/commands/copyLambdaUrl.ts
@@ -10,7 +10,7 @@ import { copyToClipboard } from '../../shared/utilities/messages'
 import { addCodiconToString } from '../../shared/utilities/textUtilities'
 import { createQuickPick, QuickPickPrompter } from '../../shared/ui/pickerPrompter'
 import { isValidResponse } from '../../shared/wizards/wizard'
-import { FunctionUrlConfigList } from 'aws-sdk/clients/lambda'
+import { FunctionUrlConfig } from '@aws-sdk/client-lambda'
 import { CancellationError } from '../../shared/utilities/timeoutUtils'
 import { lambdaFunctionUrlConfigUrl } from '../../shared/constants'
 
@@ -40,7 +40,7 @@ export async function copyLambdaUrl(
     }
 }
 
-async function _quickPickUrl(configList: FunctionUrlConfigList): Promise<string | undefined> {
+async function _quickPickUrl(configList: FunctionUrlConfig[]): Promise<string | undefined> {
     const res = await createLambdaFuncUrlPrompter(configList).prompt()
     if (!isValidResponse(res)) {
         throw new CancellationError('user')
@@ -48,10 +48,12 @@ async function _quickPickUrl(configList: FunctionUrlConfigList): Promise<string
     return res
 }
 
-export function createLambdaFuncUrlPrompter(configList: FunctionUrlConfigList): QuickPickPrompter<string> {
-    const items = configList.map((c) => ({
-        label: c.FunctionArn,
-        data: c.FunctionUrl,
-    }))
+export function createLambdaFuncUrlPrompter(configList: FunctionUrlConfig[]): QuickPickPrompter<string> {
+    const items = configList
+        .filter((c) => c.FunctionArn && c.FunctionUrl)
+        .map((c) => ({
+            label: c.FunctionArn!,
+            data: c.FunctionUrl!,
+        }))
     return createQuickPick(items, { title: 'Select function to copy url from.' })
 }
diff --git a/packages/core/src/lambda/commands/createNewSamApp.ts b/packages/core/src/lambda/commands/createNewSamApp.ts
index c53edf2518b..7801976c435 100644
--- a/packages/core/src/lambda/commands/createNewSamApp.ts
+++ b/packages/core/src/lambda/commands/createNewSamApp.ts
@@ -43,7 +43,8 @@ import { getIdeProperties, getDebugNewSamAppDocUrl, getLaunchConfigDocUrl } from
 import { checklogs } from '../../shared/localizedText'
 import globals from '../../shared/extensionGlobals'
 import { telemetry } from '../../shared/telemetry/telemetry'
-import { LambdaArchitecture, Result, Runtime } from '../../shared/telemetry/telemetry'
+import { LambdaArchitecture, Result, Runtime as TelemetryRuntime } from '../../shared/telemetry/telemetry'
+import { Runtime } from '@aws-sdk/client-lambda'
 import { getTelemetryReason, getTelemetryResult } from '../../shared/errors'
 import { openUrl, replaceVscodeVars } from '../../shared/utilities/vsCodeUtils'
 import { fs } from '../../shared/fs/fs'
@@ -88,7 +89,7 @@ export async function resumeCreateNewSamApp(
             extContext,
             folder,
             templateUri,
-            samInitState?.isImage ? (samInitState?.runtime as Runtime | undefined) : undefined
+            samInitState?.isImage ? samInitState?.runtime : undefined
         )
         const tryOpenReadme = await writeToolkitReadme(readmeUri.fsPath, configs)
         if (tryOpenReadme) {
@@ -112,7 +113,7 @@ export async function resumeCreateNewSamApp(
             lambdaArchitecture: arch,
             result: createResult,
             reason: reason,
-            runtime: samInitState?.runtime as Runtime,
+            runtime: samInitState?.runtime as TelemetryRuntime,
             version: samVersion,
         })
     }
@@ -194,7 +195,7 @@ export async function createNewSamApplication(
             initArguments.baseImage = `amazon/${createRuntime}-base`
         } else {
             lambdaPackageType = 'Zip'
-            initArguments.runtime = createRuntime
+            initArguments.runtime! = createRuntime
             // in theory, templates could be provided with image-based lambdas, but that is currently not supported by SAM
             initArguments.template = config.template
         }
@@ -348,7 +349,7 @@ export async function createNewSamApplication(
             lambdaArchitecture: initArguments?.architecture,
             result: createResult,
             reason: reason,
-            runtime: createRuntime,
+            runtime: createRuntime as TelemetryRuntime,
             version: samVersion,
         })
     }
diff --git a/packages/core/src/lambda/commands/deleteLambda.ts b/packages/core/src/lambda/commands/deleteLambda.ts
index 29dea130f66..c6290eab3c6 100644
--- a/packages/core/src/lambda/commands/deleteLambda.ts
+++ b/packages/core/src/lambda/commands/deleteLambda.ts
@@ -10,7 +10,7 @@ import * as localizedText from '../../shared/localizedText'
 import { DefaultLambdaClient } from '../../shared/clients/lambdaClient'
 import { Result } from '../../shared/telemetry/telemetry'
 import { showConfirmationMessage, showViewLogsMessage } from '../../shared/utilities/messages'
-import { FunctionConfiguration } from 'aws-sdk/clients/lambda'
+import { FunctionConfiguration } from '@aws-sdk/client-lambda'
 import { getLogger } from '../../shared/logger/logger'
 import { telemetry } from '../../shared/telemetry/telemetry'
 
diff --git a/packages/core/src/lambda/commands/uploadLambda.ts b/packages/core/src/lambda/commands/uploadLambda.ts
index 6bfd3777463..98149674587 100644
--- a/packages/core/src/lambda/commands/uploadLambda.ts
+++ b/packages/core/src/lambda/commands/uploadLambda.ts
@@ -27,7 +27,7 @@ import { StepEstimator, Wizard, WIZARD_BACK } from '../../shared/wizards/wizard'
 import { createSingleFileDialog } from '../../shared/ui/common/openDialog'
 import { Prompter, PromptResult } from '../../shared/ui/prompter'
 import { ToolkitError } from '../../shared/errors'
-import { FunctionConfiguration } from 'aws-sdk/clients/lambda'
+import { FunctionConfiguration } from '@aws-sdk/client-lambda'
 import globals from '../../shared/extensionGlobals'
 import { toArrayAsync } from '../../shared/utilities/collectionUtils'
 import { fromExtensionManifest } from '../../shared/settings'
diff --git a/packages/core/src/lambda/explorer/cloudFormationNodes.ts b/packages/core/src/lambda/explorer/cloudFormationNodes.ts
index e2d9e9aae27..4ef298a391e 100644
--- a/packages/core/src/lambda/explorer/cloudFormationNodes.ts
+++ b/packages/core/src/lambda/explorer/cloudFormationNodes.ts
@@ -6,7 +6,7 @@
 import * as nls from 'vscode-nls'
 const localize = nls.loadMessageBundle()
 
-import { CloudFormation, Lambda } from 'aws-sdk'
+import { FunctionConfiguration } from '@aws-sdk/client-lambda'
 import * as os from 'os'
 import * as vscode from 'vscode'
 import { CloudFormationClient, StackSummary } from '../../shared/clients/cloudFormation'
@@ -78,7 +78,7 @@ export class CloudFormationStackNode extends AWSTreeNodeBase implements AWSResou
         this.iconPath = getIcon('aws-cloudformation-stack')
     }
 
-    public get stackId(): CloudFormation.StackId | undefined {
+    public get stackId(): string | undefined {
         return this.stackSummary.StackId
     }
 
@@ -94,7 +94,7 @@ export class CloudFormationStackNode extends AWSTreeNodeBase implements AWSResou
         return this.stackName
     }
 
-    public get stackName(): CloudFormation.StackName {
+    public get stackName(): string {
         return this.stackSummary.StackName
     }
 
@@ -122,7 +122,7 @@ export class CloudFormationStackNode extends AWSTreeNodeBase implements AWSResou
 
     private async updateChildren(): Promise<void> {
         const resources: string[] = await this.resolveLambdaResources()
-        const functions: Map<string, Lambda.FunctionConfiguration> = toMap(
+        const functions: Map<string, FunctionConfiguration> = toMap(
             await toArrayAsync(listLambdaFunctions(this.lambdaClient)),
             (functionInfo) => functionInfo.FunctionName
         )
@@ -151,7 +151,7 @@ export class CloudFormationStackNode extends AWSTreeNodeBase implements AWSResou
 function makeCloudFormationLambdaFunctionNode(
     parent: AWSTreeNodeBase,
     regionCode: string,
-    configuration: Lambda.FunctionConfiguration
+    configuration: FunctionConfiguration
 ): LambdaFunctionNode {
     const node = new LambdaFunctionNode(parent, regionCode, configuration, contextValueCloudformationLambdaFunction)
 
diff --git a/packages/core/src/lambda/explorer/lambdaFunctionNode.ts b/packages/core/src/lambda/explorer/lambdaFunctionNode.ts
index 7b79c88659d..d2a12d0b7d6 100644
--- a/packages/core/src/lambda/explorer/lambdaFunctionNode.ts
+++ b/packages/core/src/lambda/explorer/lambdaFunctionNode.ts
@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { Lambda } from 'aws-sdk'
+import { FunctionConfiguration } from '@aws-sdk/client-lambda'
 import * as os from 'os'
 import * as vscode from 'vscode'
 import { getIcon } from '../../shared/icons'
@@ -34,7 +34,7 @@ export class LambdaFunctionNode extends AWSTreeNodeBase implements AWSResourceNo
     public constructor(
         public readonly parent: AWSTreeNodeBase,
         public override readonly regionCode: string,
-        public configuration: Lambda.FunctionConfiguration,
+        public configuration: FunctionConfiguration,
         public override readonly contextValue?: string,
         public localDir?: string
     ) {
@@ -50,7 +50,7 @@ export class LambdaFunctionNode extends AWSTreeNodeBase implements AWSResourceNo
         this.contextValue = contextValue
     }
 
-    public update(configuration: Lambda.FunctionConfiguration): void {
+    public update(configuration: FunctionConfiguration): void {
         this.configuration = configuration
         this.label = this.configuration.FunctionName || ''
         this.tooltip = `${this.configuration.FunctionName}${os.EOL}${this.configuration.FunctionArn}`
diff --git a/packages/core/src/lambda/explorer/lambdaNodes.ts b/packages/core/src/lambda/explorer/lambdaNodes.ts
index 62a01c6445a..dd753ce5594 100644
--- a/packages/core/src/lambda/explorer/lambdaNodes.ts
+++ b/packages/core/src/lambda/explorer/lambdaNodes.ts
@@ -6,7 +6,7 @@
 import * as nls from 'vscode-nls'
 const localize = nls.loadMessageBundle()
 
-import { Lambda } from 'aws-sdk'
+import { FunctionConfiguration } from '@aws-sdk/client-lambda'
 import * as vscode from 'vscode'
 import { DefaultLambdaClient } from '../../shared/clients/lambdaClient'
 
@@ -54,7 +54,7 @@ export class LambdaNode extends AWSTreeNodeBase {
     }
 
     public async updateChildren(): Promise<void> {
-        const functions: Map<string, Lambda.FunctionConfiguration> = toMap(
+        const functions: Map<string, FunctionConfiguration> = toMap(
             await toArrayAsync(listLambdaFunctions(this.client)),
             (configuration) => configuration.FunctionName
         )
@@ -71,10 +71,10 @@ export class LambdaNode extends AWSTreeNodeBase {
 function makeLambdaFunctionNode(
     parent: AWSTreeNodeBase,
     regionCode: string,
-    configuration: Lambda.FunctionConfiguration
+    configuration: FunctionConfiguration
 ): LambdaFunctionNode {
     let contextValue = contextValueLambdaFunction
-    const isImportableRuntime = samLambdaImportableRuntimes.contains(configuration.Runtime ?? '')
+    const isImportableRuntime = configuration.Runtime && samLambdaImportableRuntimes.contains(configuration.Runtime)
     if (isLocalStackConnection()) {
         if (isImportableRuntime && !isHotReloadingFunction(configuration?.CodeSha256)) {
             contextValue = contextValueLambdaFunctionDownloadOnly
diff --git a/packages/core/src/lambda/models/samLambdaRuntime.ts b/packages/core/src/lambda/models/samLambdaRuntime.ts
index 06e35dbcd2b..985e947afc9 100644
--- a/packages/core/src/lambda/models/samLambdaRuntime.ts
+++ b/packages/core/src/lambda/models/samLambdaRuntime.ts
@@ -7,7 +7,7 @@ import * as nls from 'vscode-nls'
 const localize = nls.loadMessageBundle()
 
 import * as vscode from 'vscode'
-import { Runtime } from 'aws-sdk/clients/lambda'
+import { Runtime } from '@aws-sdk/client-lambda'
 import { Map as ImmutableMap, Set as ImmutableSet } from 'immutable'
 import { isCloud9 } from '../../shared/extensionUtilities'
 import { PrompterButtons } from '../../shared/ui/buttons'
@@ -30,7 +30,7 @@ export type RuntimePackageType = 'Image' | 'Zip'
 // TODO: Consolidate all of the runtime constructs into a single <Runtime, Set<Runtime>> map
 //       We should be able to eliminate a fair amount of redundancy with that.
 export const nodeJsRuntimes: ImmutableSet<Runtime> = ImmutableSet<Runtime>([
-    'nodejs22.x',
+    'nodejs22.x' as Runtime,
     'nodejs20.x',
     'nodejs18.x',
     'nodejs16.x',
@@ -51,7 +51,7 @@ export function getNodeMajorVersion(version?: string): number | undefined {
 }
 
 export const pythonRuntimes: ImmutableSet<Runtime> = ImmutableSet<Runtime>([
-    'python3.13',
+    'python3.13' as Runtime,
     'python3.12',
     'python3.11',
     'python3.10',
@@ -68,7 +68,10 @@ export const javaRuntimes: ImmutableSet<Runtime> = ImmutableSet<Runtime>([
     'java21',
 ])
 export const dotNetRuntimes: ImmutableSet<Runtime> = ImmutableSet<Runtime>(['dotnet6', 'dotnet8'])
-export const rubyRuntimes: ImmutableSet<Runtime> = ImmutableSet<Runtime>(['ruby3.2', 'ruby3.3', 'ruby3.4'])
+export const rubyRuntimes: ImmutableSet<Runtime> = ImmutableSet<Runtime>(['ruby3.2', 'ruby3.3', 'ruby3.4' as Runtime])
+
+// Image runtimes are not a direct subset of valid ZIP lambda types
+const dotnet50 = 'dotnet5.0' as Runtime
 
 /**
  * Deprecated runtimes can be found at https://docs.aws.amazon.com/lambda/latest/dg/runtime-support-policy.html
@@ -91,8 +94,8 @@ export const deprecatedRuntimes: ImmutableSet<Runtime> = ImmutableSet<Runtime>([
     'ruby2.7',
 ])
 const defaultRuntimes = ImmutableMap<RuntimeFamily, Runtime>([
-    [RuntimeFamily.NodeJS, 'nodejs22.x'],
-    [RuntimeFamily.Python, 'python3.13'],
+    [RuntimeFamily.NodeJS, 'nodejs22.x' as Runtime],
+    [RuntimeFamily.Python, 'python3.13' as Runtime],
     [RuntimeFamily.DotNet, 'dotnet8'],
     [RuntimeFamily.Go, 'go1.x'],
     [RuntimeFamily.Java, 'java21'],
@@ -120,7 +123,7 @@ export const samZipLambdaRuntimes: ImmutableSet<Runtime> = ImmutableSet.union([
 export const samArmLambdaRuntimes: ImmutableSet<Runtime> = ImmutableSet<Runtime>([
     'python3.9',
     'python3.8',
-    'nodejs22.x',
+    'nodejs22.x' as Runtime,
     'nodejs20.x',
     'nodejs18.x',
     'nodejs16.x',
@@ -145,8 +148,6 @@ export function samLambdaCreatableRuntimes(cloud9: boolean = isCloud9()): Immuta
     return cloud9 ? cloud9SupportedRuntimes : samZipLambdaRuntimes
 }
 
-// Image runtimes are not a direct subset of valid ZIP lambda types
-const dotnet50 = 'dotnet5.0'
 export function samImageLambdaRuntimes(cloud9: boolean = isCloud9()): ImmutableSet<Runtime> {
     // Note: SAM also supports ruby, but Toolkit does not.
     return ImmutableSet<Runtime>([...samLambdaCreatableRuntimes(cloud9), ...(cloud9 ? [] : [dotnet50])])
@@ -172,7 +173,7 @@ export function getDependencyManager(runtime: Runtime): DependencyManager[] {
     throw new Error(`Runtime ${runtime} does not have an associated DependencyManager`)
 }
 
-export function getFamily(runtime: string): RuntimeFamily {
+export function getFamily(runtime: Runtime): RuntimeFamily {
     if (deprecatedRuntimes.has(runtime)) {
         handleDeprecatedRuntime(runtime)
     } else if (nodeJsRuntimes.has(runtime)) {
@@ -248,7 +249,7 @@ export function getRuntimeFamily(langId: string): RuntimeFamily {
 /**
  * Provides the default runtime for a given `RuntimeFamily` or undefined if the runtime is invalid.
  */
-export function getDefaultRuntime(runtime: RuntimeFamily): string | undefined {
+export function getDefaultRuntime(runtime: RuntimeFamily): Runtime | undefined {
     return defaultRuntimes.get(runtime)
 }
 
diff --git a/packages/core/src/lambda/models/samTemplates.ts b/packages/core/src/lambda/models/samTemplates.ts
index 5ec112a7dc4..ace9c93faf6 100644
--- a/packages/core/src/lambda/models/samTemplates.ts
+++ b/packages/core/src/lambda/models/samTemplates.ts
@@ -6,7 +6,7 @@ import * as nls from 'vscode-nls'
 const localize = nls.loadMessageBundle()
 
 import * as semver from 'semver'
-import { Runtime } from 'aws-sdk/clients/lambda'
+import { Runtime } from '@aws-sdk/client-lambda'
 import { Set as ImmutableSet } from 'immutable'
 import { supportsEventBridgeTemplates } from '../../../src/eventSchemas/models/schemaCodeLangs'
 import { RuntimePackageType } from './samLambdaRuntime'
diff --git a/packages/core/src/lambda/remoteDebugging/lambdaDebugger.ts b/packages/core/src/lambda/remoteDebugging/lambdaDebugger.ts
index 7d9867f8766..5fcb0d5048f 100644
--- a/packages/core/src/lambda/remoteDebugging/lambdaDebugger.ts
+++ b/packages/core/src/lambda/remoteDebugging/lambdaDebugger.ts
@@ -5,7 +5,7 @@
 
 import * as vscode from 'vscode'
 import globals from '../../shared/extensionGlobals'
-import type { Lambda } from 'aws-sdk'
+import { FunctionConfiguration } from '@aws-sdk/client-lambda'
 import { getLogger } from '../../shared/logger/logger'
 
 const logger = getLogger()
@@ -46,20 +46,20 @@ export interface LambdaDebugger {
     checkHealth(): Promise<void>
     setup(
         progress: vscode.Progress<{ message?: string; increment?: number }>,
-        functionConfig: Lambda.FunctionConfiguration,
+        functionConfig: FunctionConfiguration,
         region: string
     ): Promise<void>
     waitForSetup(
         progress: vscode.Progress<{ message?: string; increment?: number }>,
-        functionConfig: Lambda.FunctionConfiguration,
+        functionConfig: FunctionConfiguration,
         region: string
     ): Promise<void>
     waitForFunctionUpdates(progress: vscode.Progress<{ message?: string; increment?: number }>): Promise<void>
-    cleanup(functionConfig: Lambda.FunctionConfiguration): Promise<void>
+    cleanup(functionConfig: FunctionConfiguration): Promise<void>
 }
 
 // this should be called when the debug session is started
-export async function persistLambdaSnapshot(config: Lambda.FunctionConfiguration | undefined): Promise<void> {
+export async function persistLambdaSnapshot(config: FunctionConfiguration | undefined): Promise<void> {
     try {
         await globals.globalState.update(remoteDebugSnapshotString, config)
     } catch (error) {
@@ -68,6 +68,6 @@ export async function persistLambdaSnapshot(config: Lambda.FunctionConfiguration
     }
 }
 
-export function getLambdaSnapshot(): Lambda.FunctionConfiguration | undefined {
-    return globals.globalState.get<Lambda.FunctionConfiguration>(remoteDebugSnapshotString)
+export function getLambdaSnapshot(): FunctionConfiguration | undefined {
+    return globals.globalState.get<FunctionConfiguration>(remoteDebugSnapshotString)
 }
diff --git a/packages/core/src/lambda/remoteDebugging/ldkClient.ts b/packages/core/src/lambda/remoteDebugging/ldkClient.ts
index 4545889a7ba..a5d51adb7df 100644
--- a/packages/core/src/lambda/remoteDebugging/ldkClient.ts
+++ b/packages/core/src/lambda/remoteDebugging/ldkClient.ts
@@ -4,7 +4,7 @@
  */
 
 import * as vscode from 'vscode'
-import { Lambda } from 'aws-sdk'
+import { FunctionConfiguration } from '@aws-sdk/client-lambda'
 import {
     CloseTunnelCommand,
     IoTSecureTunnelingClient,
@@ -41,9 +41,9 @@ export interface TunnelInfo {
 
 async function callUpdateFunctionConfiguration(
     lambda: DefaultLambdaClient,
-    config: Lambda.FunctionConfiguration,
+    config: FunctionConfiguration,
     waitForUpdate: boolean
-): Promise<Lambda.FunctionConfiguration> {
+): Promise<FunctionConfiguration> {
     // Update function configuration back to original values
     return await lambda.updateFunctionConfiguration(
         {
@@ -214,7 +214,7 @@ export class LdkClient {
         }
     }
 
-    async getFunctionDetail(functionArn: string): Promise<Lambda.FunctionConfiguration | undefined> {
+    async getFunctionDetail(functionArn: string): Promise<FunctionConfiguration | undefined> {
         try {
             const region = getRegionFromArn(functionArn)
             if (!region) {
@@ -227,7 +227,7 @@ export class LdkClient {
                 return undefined
             }
             const client = this.getLambdaClient(region)
-            const configuration = (await client.getFunction(functionArn)).Configuration as Lambda.FunctionConfiguration
+            const configuration = (await client.getFunction(functionArn)).Configuration as FunctionConfiguration
             // get function detail
             // return function detail
             return configuration
@@ -244,7 +244,7 @@ export class LdkClient {
     // 3: adding two param to lambda environment variable
     // {AWS_LAMBDA_EXEC_WRAPPER:/opt/bin/ldk_wrapper, AWS_LDK_DESTINATION_TOKEN: destinationToken }
     async createDebugDeployment(
-        config: Lambda.FunctionConfiguration,
+        config: FunctionConfiguration,
         destinationToken: string,
         lambdaTimeout: number,
         shouldPublishVersion: boolean,
@@ -318,7 +318,7 @@ export class LdkClient {
             }
 
             // Create a temporary config for the update
-            const updateConfig: Lambda.FunctionConfiguration = {
+            const updateConfig: FunctionConfiguration = {
                 FunctionName: config.FunctionName,
                 Timeout: lambdaTimeout ?? 900, // 15 minutes
                 Layers: updatedLayers.map((arn) => ({ Arn: arn })),
@@ -362,7 +362,7 @@ export class LdkClient {
     // we are 1: reverting timeout to it's original snapshot
     // 2: reverting layer status according to it's original snapshot
     // 3: reverting environment back to it's original snapshot
-    async removeDebugDeployment(config: Lambda.FunctionConfiguration, check: boolean = true): Promise<boolean> {
+    async removeDebugDeployment(config: FunctionConfiguration, check: boolean = true): Promise<boolean> {
         try {
             if (!config.FunctionArn || !config.FunctionName) {
                 throw new Error('Function ARN is missing')
diff --git a/packages/core/src/lambda/remoteDebugging/ldkController.ts b/packages/core/src/lambda/remoteDebugging/ldkController.ts
index 2b5553a8a05..83808f5f525 100644
--- a/packages/core/src/lambda/remoteDebugging/ldkController.ts
+++ b/packages/core/src/lambda/remoteDebugging/ldkController.ts
@@ -6,7 +6,7 @@
 import * as vscode from 'vscode'
 import { getLogger } from '../../shared/logger/logger'
 import globals from '../../shared/extensionGlobals'
-import type { Lambda } from 'aws-sdk'
+import { FunctionConfiguration, Runtime } from '@aws-sdk/client-lambda'
 import { getRegionFromArn, LdkClient } from './ldkClient'
 import { getFamily, mapFamilyToDebugType } from '../models/samLambdaRuntime'
 import { findJavaPath } from '../../shared/utilities/pathFind'
@@ -35,8 +35,8 @@ const mapExtensionToBackup = new Map<string, string>([['ms-vscode.js-debug', 'ms
 
 // Helper function to create a human-readable diff message
 function createDiffMessage(
-    config: Lambda.FunctionConfiguration,
-    currentConfig: Lambda.FunctionConfiguration,
+    config: FunctionConfiguration,
+    currentConfig: FunctionConfiguration,
     isRevert: boolean = true
 ): string {
     let message = isRevert ? 'The following changes will be reverted:\n\n' : 'The following changes will be made:\n\n'
@@ -248,7 +248,7 @@ function processOutFiles(outFiles: string[], localRoot: string): string[] {
 }
 
 async function getVscodeDebugConfig(
-    functionConfig: Lambda.FunctionConfiguration,
+    functionConfig: FunctionConfiguration,
     debugConfig: DebugConfig
 ): Promise<vscode.DebugConfiguration> {
     // Parse and validate otherDebugParams if provided
@@ -283,7 +283,7 @@ async function getVscodeDebugConfig(
     const debugSessionName = `Debug ${functionConfig.FunctionArn!.split(':').pop()}`
 
     // Define debugConfig before the try block
-    const debugType = mapFamilyToDebugType.get(getFamily(functionConfig.Runtime ?? ''), 'unknown')
+    const debugType = mapFamilyToDebugType.get(getFamily(functionConfig.Runtime!), 'unknown')
     let vsCodeDebugConfig: vscode.DebugConfiguration
     switch (debugType) {
         case 'node':
@@ -410,7 +410,7 @@ export class RemoteDebugController {
         }
     }
 
-    public supportCodeDownload(runtime: string | undefined, codeSha256: string | undefined = ''): boolean {
+    public supportCodeDownload(runtime: Runtime | undefined, codeSha256: string | undefined = ''): boolean {
         if (!runtime) {
             return false
         }
@@ -426,7 +426,7 @@ export class RemoteDebugController {
         }
     }
 
-    public supportRuntimeRemoteDebug(runtime: string | undefined): boolean {
+    public supportRuntimeRemoteDebug(runtime: Runtime | undefined): boolean {
         if (!runtime) {
             return false
         }
@@ -437,7 +437,7 @@ export class RemoteDebugController {
         }
     }
 
-    public async installDebugExtension(runtime: string | undefined): Promise<boolean | undefined> {
+    public async installDebugExtension(runtime: Runtime | undefined): Promise<boolean | undefined> {
         if (!runtime) {
             throw new ToolkitError('Runtime is undefined')
         }
@@ -551,7 +551,7 @@ export class RemoteDebugController {
                     }
 
                     // Check if runtime / region is supported for remote debugging
-                    if (!this.supportRuntimeRemoteDebug(runtime)) {
+                    if (!this.supportRuntimeRemoteDebug(runtime as Runtime)) {
                         throw new ToolkitError(
                             `Runtime ${runtime} is not supported for remote debugging. ` +
                                 `Only Python, Node.js, and Java runtimes are supported.`
diff --git a/packages/core/src/lambda/remoteDebugging/localStackLambdaDebugger.ts b/packages/core/src/lambda/remoteDebugging/localStackLambdaDebugger.ts
index a7d98f06668..d74b6ac3471 100644
--- a/packages/core/src/lambda/remoteDebugging/localStackLambdaDebugger.ts
+++ b/packages/core/src/lambda/remoteDebugging/localStackLambdaDebugger.ts
@@ -4,7 +4,7 @@
  */
 
 import * as vscode from 'vscode'
-import type { Lambda } from 'aws-sdk'
+import { FunctionConfiguration } from '@aws-sdk/client-lambda'
 import globals from '../../shared/extensionGlobals'
 import { persistLambdaSnapshot, type LambdaDebugger, type DebugConfig } from './lambdaDebugger'
 import { getLambdaClientWithAgent, getLambdaDebugUserAgent } from './utils'
@@ -35,7 +35,7 @@ export class LocalStackLambdaDebugger implements LambdaDebugger {
 
     public async setup(
         progress: vscode.Progress<{ message?: string; increment?: number }>,
-        functionConfig: Lambda.FunctionConfiguration,
+        functionConfig: FunctionConfiguration,
         region: string
     ): Promise<void> {
         // No function update and version publishing needed for LocalStack
@@ -95,7 +95,7 @@ export class LocalStackLambdaDebugger implements LambdaDebugger {
 
     public async waitForSetup(
         progress: vscode.Progress<{ message?: string; increment?: number }>,
-        functionConfig: Lambda.FunctionConfiguration,
+        functionConfig: FunctionConfiguration,
         region: string
     ): Promise<void> {
         if (!functionConfig?.FunctionArn) {
@@ -142,7 +142,7 @@ export class LocalStackLambdaDebugger implements LambdaDebugger {
         // b) Invokes for debug-enabled await being served until the debugger is connected
     }
 
-    public async cleanup(functionConfig: Lambda.FunctionConfiguration): Promise<void> {
+    public async cleanup(functionConfig: FunctionConfiguration): Promise<void> {
         await vscode.commands.executeCommand('workbench.action.debug.stop')
 
         const endpointUrl = globals.awsContext.getCredentialEndpointUrl()
diff --git a/packages/core/src/lambda/remoteDebugging/remoteLambdaDebugger.ts b/packages/core/src/lambda/remoteDebugging/remoteLambdaDebugger.ts
index 716f91d7e01..afc9f83abcd 100644
--- a/packages/core/src/lambda/remoteDebugging/remoteLambdaDebugger.ts
+++ b/packages/core/src/lambda/remoteDebugging/remoteLambdaDebugger.ts
@@ -4,7 +4,7 @@
  */
 
 import * as vscode from 'vscode'
-import type { Lambda } from 'aws-sdk'
+import { Architecture, FunctionConfiguration } from '@aws-sdk/client-lambda'
 import { persistLambdaSnapshot, type LambdaDebugger, type DebugConfig } from './lambdaDebugger'
 import { getLogger } from '../../shared/logger/logger'
 import { isTunnelInfo, LdkClient } from './ldkClient'
@@ -14,7 +14,7 @@ import { getRemoteDebugLayerForArch } from './ldkLayers'
 
 export function getRemoteDebugLayer(
     region: string | undefined,
-    architectures: Lambda.ArchitecturesList | undefined
+    architectures: Architecture[] | undefined
 ): string | undefined {
     if (!region || !architectures) {
         return undefined
@@ -50,7 +50,7 @@ export class RemoteLambdaDebugger implements LambdaDebugger {
 
     public async setup(
         progress: vscode.Progress<{ message?: string; increment?: number }>,
-        functionConfig: Lambda.FunctionConfiguration,
+        functionConfig: FunctionConfiguration,
         region: string
     ): Promise<void> {
         const ldkClient = LdkClient.instance
@@ -87,7 +87,7 @@ export class RemoteLambdaDebugger implements LambdaDebugger {
 
     public async waitForSetup(
         progress: vscode.Progress<{ message?: string; increment?: number }>,
-        functionConfig: Lambda.FunctionConfiguration,
+        functionConfig: FunctionConfiguration,
         region: string
     ): Promise<void> {
         if (!this.tunnelInfo) {
@@ -131,7 +131,7 @@ export class RemoteLambdaDebugger implements LambdaDebugger {
         }
     }
 
-    public async cleanup(functionConfig: Lambda.FunctionConfiguration): Promise<void> {
+    public async cleanup(functionConfig: FunctionConfiguration): Promise<void> {
         const ldkClient = LdkClient.instance
         if (!functionConfig?.FunctionArn) {
             throw new ToolkitError('No saved configuration found during cleanup')
diff --git a/packages/core/src/lambda/utils.ts b/packages/core/src/lambda/utils.ts
index a17783d37b8..9b8ffcb884a 100644
--- a/packages/core/src/lambda/utils.ts
+++ b/packages/core/src/lambda/utils.ts
@@ -8,7 +8,7 @@ const localize = nls.loadMessageBundle()
 
 import path from 'path'
 import xml2js = require('xml2js')
-import { Lambda } from 'aws-sdk'
+import { FunctionConfiguration, LayerVersionsListItem } from '@aws-sdk/client-lambda'
 import * as vscode from 'vscode'
 import { CloudFormationClient, StackSummary } from '../shared/clients/cloudFormation'
 import { DefaultLambdaClient, LambdaClient } from '../shared/clients/lambdaClient'
@@ -36,7 +36,7 @@ export async function* listCloudFormationStacks(client: CloudFormationClient): A
     }
 }
 
-export async function* listLambdaFunctions(client: LambdaClient): AsyncIterableIterator<Lambda.FunctionConfiguration> {
+export async function* listLambdaFunctions(client: LambdaClient): AsyncIterableIterator<FunctionConfiguration> {
     const status = vscode.window.setStatusBarMessage(
         localize('AWS.message.statusBar.loading.lambda', 'Loading Lambdas...')
     )
@@ -53,7 +53,7 @@ export async function* listLambdaFunctions(client: LambdaClient): AsyncIterableI
 export async function* listLayerVersions(
     client: LambdaClient,
     name: string
-): AsyncIterableIterator<Lambda.LayerVersionsListItem> {
+): AsyncIterableIterator<LayerVersionsListItem> {
     const status = vscode.window.setStatusBarMessage(
         localize('AWS.message.statusBar.loading.lambda', 'Loading Lambda Layer Versions...')
     )
@@ -72,7 +72,7 @@ export async function* listLayerVersions(
  * Only works for supported languages (Python/JS)
  * @param configuration Lambda configuration object from getFunction
  */
-export function getLambdaDetails(configuration: Lambda.FunctionConfiguration): {
+export function getLambdaDetails(configuration: FunctionConfiguration): {
     fileName: string
     functionName: string
 } {
diff --git a/packages/core/src/lambda/vue/remoteInvoke/invokeLambda.ts b/packages/core/src/lambda/vue/remoteInvoke/invokeLambda.ts
index d745de85f3e..9f72902f9e4 100644
--- a/packages/core/src/lambda/vue/remoteInvoke/invokeLambda.ts
+++ b/packages/core/src/lambda/vue/remoteInvoke/invokeLambda.ts
@@ -3,7 +3,6 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { _Blob } from 'aws-sdk/clients/lambda'
 import { readFileSync } from 'fs' // eslint-disable-line no-restricted-imports
 import * as _ from 'lodash'
 import * as vscode from 'vscode'
@@ -19,7 +18,8 @@ import { getSampleLambdaPayloads, SampleRequest, isHotReloadingFunction } from '
 
 import * as nls from 'vscode-nls'
 import { VueWebview } from '../../../webviews/main'
-import { telemetry, Runtime } from '../../../shared/telemetry/telemetry'
+import { telemetry, Runtime as TelemetryRuntime } from '../../../shared/telemetry/telemetry'
+import { Runtime } from '@aws-sdk/client-lambda'
 import {
     runSamCliRemoteTestEvents,
     SamCliRemoteTestEventsParameters,
@@ -58,7 +58,7 @@ export interface InitialData {
     Source?: string
     StackName?: string
     LogicalId?: string
-    Runtime?: string
+    Runtime?: Runtime
     LocalRootPath?: string
     LambdaFunctionNode?: LambdaFunctionNode
     supportCodeDownload?: boolean
@@ -294,7 +294,8 @@ export class RemoteInvokeWebview extends VueWebview {
                     ? await this.clientDebug.invoke(this.data.FunctionArn, input, qualifier)
                     : await this.client.invoke(this.data.FunctionArn, input, qualifier)
                 const logs = funcResponse.LogResult ? decodeBase64(funcResponse.LogResult) : ''
-                const payload = funcResponse.Payload ? funcResponse.Payload : JSON.stringify({})
+                const decodedPayload = funcResponse.Payload ? new TextDecoder().decode(funcResponse.Payload) : ''
+                const payload = decodedPayload || JSON.stringify({})
 
                 this.channel.appendLine(`Invocation result for ${this.data.FunctionArn}`)
                 this.channel.appendLine('Logs:')
@@ -393,12 +394,14 @@ export class RemoteInvokeWebview extends VueWebview {
             return false
         }
 
-        const handlerFile = await getLambdaHandlerFile(
-            vscode.Uri.file(this.data.LocalRootPath),
-            '',
-            this.data.LambdaFunctionNode?.configuration.Handler ?? '',
-            this.data.Runtime ?? 'unknown'
-        )
+        const handlerFile = this.data.Runtime
+            ? await getLambdaHandlerFile(
+                  vscode.Uri.file(this.data.LocalRootPath),
+                  '',
+                  this.data.LambdaFunctionNode?.configuration.Handler ?? '',
+                  this.data.Runtime
+              )
+            : undefined
         if (!handlerFile || !(await fs.exists(handlerFile))) {
             this.handlerFileAvailable = false
             return false
@@ -517,7 +520,7 @@ export class RemoteInvokeWebview extends VueWebview {
     // Download lambda code and update the local root path
     public async downloadRemoteCode(): Promise<string | undefined> {
         return await telemetry.lambda_import.run(async (span) => {
-            span.record({ runtime: this.data.Runtime as Runtime | undefined, source: 'RemoteDebug' })
+            span.record({ runtime: this.data.Runtime as TelemetryRuntime | undefined, source: 'RemoteDebug' })
             try {
                 if (this.data.LambdaFunctionNode) {
                     const output = await runDownloadLambda(this.data.LambdaFunctionNode, true)
@@ -762,7 +765,7 @@ export async function invokeRemoteLambda(
     const Panel = VueWebview.compilePanel(RemoteInvokeWebview)
 
     // Initialize support and debugging capabilities
-    const runtime = resource.configuration.Runtime ?? 'unknown'
+    const runtime = resource.configuration.Runtime
     const region = resource.regionCode
     const supportCodeDownload = RemoteDebugController.instance.supportCodeDownload(
         runtime,
diff --git a/packages/core/src/lambda/wizards/samInitWizard.ts b/packages/core/src/lambda/wizards/samInitWizard.ts
index 10906ec513d..9bd3a1b72fb 100644
--- a/packages/core/src/lambda/wizards/samInitWizard.ts
+++ b/packages/core/src/lambda/wizards/samInitWizard.ts
@@ -5,7 +5,7 @@
 
 import * as nls from 'vscode-nls'
 import * as AWS from '@aws-sdk/types'
-import { Runtime } from 'aws-sdk/clients/lambda'
+import { Runtime } from '@aws-sdk/client-lambda'
 import * as path from 'path'
 import * as vscode from 'vscode'
 import { SchemasDataProvider } from '../../eventSchemas/providers/schemasDataProvider'
@@ -231,7 +231,7 @@ export class CreateNewSamAppWizard extends Wizard<CreateNewSamAppWizardForm> {
                 return false
             }
 
-            return samArmLambdaRuntimes.has(state.runtimeAndPackage?.runtime ?? 'unknown')
+            return state.runtimeAndPackage ? samArmLambdaRuntimes.has(state.runtimeAndPackage.runtime) : false
         }
 
         this.form.architecture.bindPrompter(createArchitecturePrompter, {
diff --git a/packages/core/src/shared/activationReloadState.ts b/packages/core/src/shared/activationReloadState.ts
index 70d236d2dd0..bcdefa925f3 100644
--- a/packages/core/src/shared/activationReloadState.ts
+++ b/packages/core/src/shared/activationReloadState.ts
@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { Runtime } from 'aws-sdk/clients/lambda'
+import { Runtime } from '@aws-sdk/client-lambda'
 import globals from './extensionGlobals'
 
 export interface SamInitState {
@@ -22,7 +22,7 @@ export class ActivationReloadState {
         return {
             template: globals.globalState.get<string>('ACTIVATION_TEMPLATE_PATH_KEY'),
             readme: globals.globalState.get<string>('ACTIVATION_LAUNCH_PATH_KEY'),
-            runtime: globals.globalState.get<string>('SAM_INIT_RUNTIME_KEY'),
+            runtime: globals.globalState.get<Runtime>('SAM_INIT_RUNTIME_KEY'),
             architecture: globals.globalState.get<string>('SAM_INIT_ARCH_KEY'),
             isImage: globals.globalState.get<boolean>('SAM_INIT_IMAGE_BOOLEAN_KEY'),
         }
diff --git a/packages/core/src/shared/clients/lambdaClient.ts b/packages/core/src/shared/clients/lambdaClient.ts
index 949b80b2fee..d6805bf4a25 100644
--- a/packages/core/src/shared/clients/lambdaClient.ts
+++ b/packages/core/src/shared/clients/lambdaClient.ts
@@ -3,18 +3,45 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { Lambda } from 'aws-sdk'
-import { _Blob } from 'aws-sdk/clients/lambda'
+import { BlobPayloadInputTypes } from '@smithy/types'
 import { ToolkitError } from '../errors'
 import globals from '../extensionGlobals'
 import { getLogger } from '../logger/logger'
 import { ClassToInterfaceType } from '../utilities/tsUtils'
 
-import { LambdaClient as LambdaSdkClient, GetFunctionCommand, GetFunctionCommandOutput } from '@aws-sdk/client-lambda'
+import {
+    LambdaClient as LambdaSdkClient,
+    GetFunctionCommand,
+    GetFunctionCommandOutput,
+    FunctionConfiguration,
+    InvocationResponse,
+    ListFunctionsRequest,
+    ListFunctionsResponse,
+    GetFunctionResponse,
+    GetLayerVersionResponse,
+    ListLayerVersionsRequest,
+    LayerVersionsListItem,
+    ListLayerVersionsResponse,
+    UpdateFunctionConfigurationRequest,
+    FunctionUrlConfig,
+    GetFunctionConfigurationCommand,
+    PublishVersionCommand,
+    UpdateFunctionConfigurationCommand,
+    UpdateFunctionCodeCommand,
+    ListFunctionUrlConfigsCommand,
+    ListLayerVersionsCommand,
+    GetLayerVersionCommand,
+    ListFunctionsCommand,
+    DeleteFunctionCommand,
+    InvokeCommand,
+    waitUntilFunctionUpdatedV2,
+    waitUntilFunctionActiveV2,
+} from '@aws-sdk/client-lambda'
 import { CancellationError } from '../utilities/timeoutUtils'
 import { fromSSO } from '@aws-sdk/credential-provider-sso'
 import { getIAMConnection } from '../../auth/utils'
 import { WaiterConfiguration } from 'aws-sdk/lib/service'
+import { NodeHttpHandler } from '@smithy/node-http-handler'
 
 export type LambdaClient = ClassToInterfaceType<DefaultLambdaClient>
 
@@ -31,39 +58,35 @@ export class DefaultLambdaClient {
     public async deleteFunction(name: string, qualifier?: string): Promise<void> {
         const sdkClient = await this.createSdkClient()
 
-        const response = await sdkClient
-            .deleteFunction({
+        await sdkClient.send(
+            new DeleteFunctionCommand({
                 FunctionName: name,
                 Qualifier: qualifier,
             })
-            .promise()
-
-        if (response.$response.error) {
-            throw response.$response.error
-        }
+        )
     }
 
-    public async invoke(name: string, payload?: _Blob, version?: string): Promise<Lambda.InvocationResponse> {
+    public async invoke(name: string, payload?: BlobPayloadInputTypes, version?: string): Promise<InvocationResponse> {
         const sdkClient = await this.createSdkClient()
 
-        const response = await sdkClient
-            .invoke({
+        const response = await sdkClient.send(
+            new InvokeCommand({
                 FunctionName: name,
                 LogType: 'Tail',
                 Payload: payload,
                 Qualifier: version,
             })
-            .promise()
+        )
 
         return response
     }
 
-    public async *listFunctions(): AsyncIterableIterator<Lambda.FunctionConfiguration> {
+    public async *listFunctions(): AsyncIterableIterator<FunctionConfiguration> {
         const client = await this.createSdkClient()
 
-        const request: Lambda.ListFunctionsRequest = {}
+        const request: ListFunctionsRequest = {}
         do {
-            const response: Lambda.ListFunctionsResponse = await client.listFunctions(request).promise()
+            const response: ListFunctionsResponse = await client.send(new ListFunctionsCommand(request))
 
             if (response.Functions) {
                 yield* response.Functions
@@ -73,12 +96,12 @@ export class DefaultLambdaClient {
         } while (request.Marker)
     }
 
-    public async getFunction(name: string): Promise<Lambda.GetFunctionResponse> {
+    public async getFunction(name: string): Promise<GetFunctionResponse> {
         getLogger().debug(`GetFunction called for function: ${name}`)
         const client = await this.createSdkClient()
 
         try {
-            const response = await client.getFunction({ FunctionName: name }).promise()
+            const response = await client.send(new GetFunctionCommand({ FunctionName: name }))
             // prune `Code` from logs so we don't reveal a signed link to customer resources.
             getLogger().debug('GetFunction returned response (code section pruned): %O', {
                 ...response,
@@ -91,12 +114,12 @@ export class DefaultLambdaClient {
         }
     }
 
-    public async getLayerVersion(name: string, version: number): Promise<Lambda.GetLayerVersionResponse> {
+    public async getLayerVersion(name: string, version: number): Promise<GetLayerVersionResponse> {
         getLogger().debug(`getLayerVersion called for LayerName: ${name}, VersionNumber ${version}`)
         const client = await this.createSdkClient()
 
         try {
-            const response = await client.getLayerVersion({ LayerName: name, VersionNumber: version }).promise()
+            const response = await client.send(new GetLayerVersionCommand({ LayerName: name, VersionNumber: version }))
             // prune `Code` from logs so we don't reveal a signed link to customer resources.
             getLogger().debug('getLayerVersion returned response (code section pruned): %O', {
                 ...response,
@@ -109,12 +132,12 @@ export class DefaultLambdaClient {
         }
     }
 
-    public async *listLayerVersions(name: string): AsyncIterableIterator<Lambda.LayerVersionsListItem> {
+    public async *listLayerVersions(name: string): AsyncIterableIterator<LayerVersionsListItem> {
         const client = await this.createSdkClient()
 
-        const request: Lambda.ListLayerVersionsRequest = { LayerName: name }
+        const request: ListLayerVersionsRequest = { LayerName: name }
         do {
-            const response: Lambda.ListLayerVersionsResponse = await client.listLayerVersions(request).promise()
+            const response: ListLayerVersionsResponse = await client.send(new ListLayerVersionsCommand(request))
 
             if (response.LayerVersions) {
                 yield* response.LayerVersions
@@ -124,38 +147,37 @@ export class DefaultLambdaClient {
         } while (request.Marker)
     }
 
-    public async getFunctionUrlConfigs(name: string): Promise<Lambda.FunctionUrlConfigList> {
+    public async getFunctionUrlConfigs(name: string): Promise<FunctionUrlConfig[]> {
         getLogger().debug(`GetFunctionUrlConfig called for function: ${name}`)
         const client = await this.createSdkClient()
 
         try {
-            const request = client.listFunctionUrlConfigs({ FunctionName: name })
-            const response = await request.promise()
+            const response = await client.send(new ListFunctionUrlConfigsCommand({ FunctionName: name }))
             // prune `Code` from logs so we don't reveal a signed link to customer resources.
             getLogger().debug('GetFunctionUrlConfig returned response (code section pruned): %O', {
                 ...response,
                 Code: 'Pruned',
             })
-            return response.FunctionUrlConfigs
+            return response.FunctionUrlConfigs ?? []
         } catch (e) {
             throw ToolkitError.chain(e, 'Failed to get Lambda function URLs')
         }
     }
 
-    public async updateFunctionCode(name: string, zipFile: Uint8Array): Promise<Lambda.FunctionConfiguration> {
+    public async updateFunctionCode(name: string, zipFile: Uint8Array): Promise<FunctionConfiguration> {
         getLogger().debug(`updateFunctionCode called for function: ${name}`)
         const client = await this.createSdkClient()
 
         try {
-            const response = await client
-                .updateFunctionCode({
+            const response = await client.send(
+                new UpdateFunctionCodeCommand({
                     FunctionName: name,
                     Publish: true,
                     ZipFile: zipFile,
                 })
-                .promise()
+            )
             getLogger().debug('updateFunctionCode returned response: %O', response)
-            await client.waitFor('functionUpdated', { FunctionName: name }).promise()
+            await waitUntilFunctionUpdatedV2({ client, maxWaitTime: 300 }, { FunctionName: name })
 
             return response
         } catch (e) {
@@ -165,14 +187,14 @@ export class DefaultLambdaClient {
     }
 
     public async updateFunctionConfiguration(
-        params: Lambda.UpdateFunctionConfigurationRequest,
+        params: UpdateFunctionConfigurationRequest,
         options: {
             maxRetries?: number
             initialDelayMs?: number
             backoffMultiplier?: number
             waitForUpdate?: boolean
         } = {}
-    ): Promise<Lambda.FunctionConfiguration> {
+    ): Promise<FunctionConfiguration> {
         const client = await this.createSdkClient()
         const maxRetries = options.maxRetries ?? 5
         const initialDelayMs = options.initialDelayMs ?? 1000
@@ -186,7 +208,7 @@ export class DefaultLambdaClient {
         // there could be race condition, if function is being updated, wait and retry
         while (retryCount <= maxRetries) {
             try {
-                const response = await client.updateFunctionConfiguration(params).promise()
+                const response = await client.send(new UpdateFunctionConfigurationCommand(params))
                 getLogger().debug('updateFunctionConfiguration returned response: %O', response)
                 if (waitForUpdate) {
                     // don't return if wait for result
@@ -219,7 +241,9 @@ export class DefaultLambdaClient {
             let lastUpdateStatus = 'InProgress'
             while (lastUpdateStatus === 'InProgress') {
                 await new Promise((resolve) => setTimeout(resolve, 1000))
-                const response = await client.getFunctionConfiguration({ FunctionName: params.FunctionName }).promise()
+                const response = await client.send(
+                    new GetFunctionConfigurationCommand({ FunctionName: params.FunctionName })
+                )
                 lastUpdateStatus = response.LastUpdateStatus ?? 'Failed'
                 if (lastUpdateStatus === 'Successful') {
                     return response
@@ -237,23 +261,23 @@ export class DefaultLambdaClient {
     public async publishVersion(
         name: string,
         options: { waitForUpdate?: boolean } = {}
-    ): Promise<Lambda.FunctionConfiguration> {
+    ): Promise<FunctionConfiguration> {
         const client = await this.createSdkClient()
         // return until lambda update is completed
         const waitForUpdate = options.waitForUpdate ?? false
-        const response = await client
-            .publishVersion({
+        const response = await client.send(
+            new PublishVersionCommand({
                 FunctionName: name,
             })
-            .promise()
+        )
 
         if (waitForUpdate) {
             let state = 'Pending'
             while (state === 'Pending') {
                 await new Promise((resolve) => setTimeout(resolve, 1000))
-                const statusResponse = await client
-                    .getFunctionConfiguration({ FunctionName: name, Qualifier: response.Version })
-                    .promise()
+                const statusResponse = await client.send(
+                    new GetFunctionConfigurationCommand({ FunctionName: name, Qualifier: response.Version })
+                )
                 state = statusResponse.State ?? 'Failed'
                 if (state === 'Active' || state === 'InActive') {
                     // version creation finished
@@ -280,27 +304,24 @@ export class DefaultLambdaClient {
     public async waitForActive(functionName: string, waiter?: WaiterConfiguration): Promise<void> {
         const sdkClient = await this.createSdkClient()
 
-        await sdkClient
-            .waitFor('functionActive', {
-                FunctionName: functionName,
-                $waiter: waiter ?? {
-                    delay: 1,
-                    // In LocalStack, it requires 2 MBit/s connection to download ~150 MB Lambda image in 600 seconds
-                    maxAttempts: 600,
-                },
-            })
-            .promise()
+        await waitUntilFunctionActiveV2(
+            { client: sdkClient, maxWaitTime: (waiter?.maxAttempts ?? 600) * (waiter?.delay ?? 1) },
+            { FunctionName: functionName }
+        )
     }
 
-    private async createSdkClient(): Promise<Lambda> {
-        return await globals.sdkClientBuilder.createAwsService(
-            Lambda,
-            {
-                httpOptions: { timeout: this.defaultTimeoutInMs },
-                customUserAgent: this.userAgent,
+    private async createSdkClient(): Promise<LambdaSdkClient> {
+        return globals.sdkClientBuilderV3.createAwsService({
+            serviceClient: LambdaSdkClient,
+            userAgent: !this.userAgent,
+            clientOptions: {
+                userAgent: this.userAgent ? [[this.userAgent]] : undefined,
+                region: this.regionCode,
+                requestHandler: new NodeHttpHandler({
+                    requestTimeout: this.defaultTimeoutInMs,
+                }),
             },
-            this.regionCode
-        )
+        })
     }
 }
 
diff --git a/packages/core/src/shared/fs/templateRegistry.ts b/packages/core/src/shared/fs/templateRegistry.ts
index 00afe876c4d..a9ec3a66ac8 100644
--- a/packages/core/src/shared/fs/templateRegistry.ts
+++ b/packages/core/src/shared/fs/templateRegistry.ts
@@ -18,6 +18,7 @@ import { Timeout } from '../utilities/timeoutUtils'
 import { localize } from '../utilities/vsCodeUtils'
 import { PerfLog } from '../logger/perfLogger'
 import { showMessageWithCancel } from '../utilities/messages'
+import { Runtime } from '@aws-sdk/client-lambda'
 
 export class CloudFormationTemplateRegistry extends WatchedFiles<CloudFormation.Template> {
     public name: string = 'CloudFormationTemplateRegistry'
@@ -188,7 +189,7 @@ export function getResourcesForHandlerFromTemplateDatum(
                 resource.Properties,
                 'Runtime',
                 templateDatum.item
-            )
+            ) as Runtime
             const registeredCodeUri = CloudFormation.getStringForProperty(
                 resource.Properties,
                 'CodeUri',
diff --git a/packages/core/src/shared/sam/cli/samCliInit.ts b/packages/core/src/shared/sam/cli/samCliInit.ts
index b087b7cc5f4..366c7539519 100644
--- a/packages/core/src/shared/sam/cli/samCliInit.ts
+++ b/packages/core/src/shared/sam/cli/samCliInit.ts
@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { Runtime } from 'aws-sdk/clients/lambda'
+import { Runtime } from '@aws-sdk/client-lambda'
 import { SchemaTemplateExtraContext } from '../../../eventSchemas/templates/schemasAppTemplateUtils'
 import { Architecture, DependencyManager } from '../../../lambda/models/samLambdaRuntime'
 import { getSamCliTemplateParameter, SamTemplate } from '../../../lambda/models/samTemplates'
diff --git a/packages/core/src/shared/sam/cli/samCliLocalInvoke.ts b/packages/core/src/shared/sam/cli/samCliLocalInvoke.ts
index 265b0c86338..c1e60ebcb41 100644
--- a/packages/core/src/shared/sam/cli/samCliLocalInvoke.ts
+++ b/packages/core/src/shared/sam/cli/samCliLocalInvoke.ts
@@ -15,7 +15,7 @@ import globals from '../../extensionGlobals'
 import { SamCliSettings } from './samCliSettings'
 import { addTelemetryEnvVar, collectSamErrors, SamCliError } from './samCliInvokerUtils'
 import { fs } from '../../fs/fs'
-import { Runtime } from 'aws-sdk/clients/lambda'
+import { Runtime } from '@aws-sdk/client-lambda'
 import { getSamCliPathAndVersion } from '../utils'
 import { deprecatedRuntimes } from '../../../lambda/models/samLambdaRuntime'
 
diff --git a/packages/core/src/shared/sam/debugger/awsSamDebugConfiguration.ts b/packages/core/src/shared/sam/debugger/awsSamDebugConfiguration.ts
index 389b91f6208..f11be86d00c 100644
--- a/packages/core/src/shared/sam/debugger/awsSamDebugConfiguration.ts
+++ b/packages/core/src/shared/sam/debugger/awsSamDebugConfiguration.ts
@@ -5,7 +5,7 @@
 
 import * as vscode from 'vscode'
 import * as path from 'path'
-import { Runtime } from 'aws-sdk/clients/lambda'
+import { Runtime } from '@aws-sdk/client-lambda'
 import { getNormalizedRelativePath } from '../../utilities/pathUtils'
 import {
     APIGatewayProperties,
diff --git a/packages/core/src/shared/sam/debugger/awsSamDebugConfigurationValidator.ts b/packages/core/src/shared/sam/debugger/awsSamDebugConfigurationValidator.ts
index f71310f0261..b400746d7e6 100644
--- a/packages/core/src/shared/sam/debugger/awsSamDebugConfigurationValidator.ts
+++ b/packages/core/src/shared/sam/debugger/awsSamDebugConfigurationValidator.ts
@@ -20,6 +20,7 @@ import {
 } from './awsSamDebugConfiguration'
 import { tryGetAbsolutePath } from '../../utilities/workspaceUtils'
 import { CloudFormationTemplateRegistry } from '../../fs/templateRegistry'
+import { Runtime } from '@aws-sdk/client-lambda'
 
 export interface ValidationResult {
     isValid: boolean
@@ -187,7 +188,7 @@ export class DefaultAwsSamDebugConfigurationValidator implements AwsSamDebugConf
                 }
             }
             // can't infer the runtime for image-based lambdas
-            if (!config.lambda?.runtime || !samImageLambdaRuntimes().has(config.lambda.runtime)) {
+            if (!config.lambda?.runtime || !samImageLambdaRuntimes().has(config.lambda.runtime as Runtime)) {
                 return {
                     isValid: false,
                     message: localize(
@@ -201,7 +202,7 @@ export class DefaultAwsSamDebugConfigurationValidator implements AwsSamDebugConf
             // TODO: Decide what to do with this re: refs.
             // As of now, this has to be directly declared without a ref, despite the fact that SAM will handle a ref.
             // Should we just pass validation off to SAM and ignore validation at this point, or should we directly process the value (like the handler)?
-            const runtime = CloudFormation.getStringForProperty(resource?.Properties, 'Runtime', cfnTemplate)
+            const runtime = CloudFormation.getStringForProperty(resource?.Properties, 'Runtime', cfnTemplate) as Runtime
             if (!runtime || !samZipLambdaRuntimes.has(runtime)) {
                 return {
                     isValid: false,
@@ -262,7 +263,10 @@ export class DefaultAwsSamDebugConfigurationValidator implements AwsSamDebugConf
     }
 
     private validateCodeConfig(debugConfiguration: AwsSamDebuggerConfiguration): ValidationResult {
-        if (!debugConfiguration.lambda?.runtime || !samZipLambdaRuntimes.has(debugConfiguration.lambda.runtime)) {
+        if (
+            !debugConfiguration.lambda?.runtime ||
+            !samZipLambdaRuntimes.has(debugConfiguration.lambda.runtime as Runtime)
+        ) {
             return {
                 isValid: false,
                 message: localize(
diff --git a/packages/core/src/shared/sam/debugger/awsSamDebugger.ts b/packages/core/src/shared/sam/debugger/awsSamDebugger.ts
index 2b6e9311e6b..217ce451dcd 100644
--- a/packages/core/src/shared/sam/debugger/awsSamDebugger.ts
+++ b/packages/core/src/shared/sam/debugger/awsSamDebugger.ts
@@ -59,7 +59,8 @@ import { minSamCliVersionForImageSupport, minSamCliVersionForGoSupport } from '.
 import { getIdeProperties } from '../../extensionUtilities'
 import { resolve } from 'path'
 import globals from '../../extensionGlobals'
-import { Runtime, telemetry } from '../../telemetry/telemetry'
+import { telemetry, Runtime as TelemetryRuntime } from '../../telemetry/telemetry'
+import { Runtime } from '@aws-sdk/client-lambda'
 import { ErrorInformation, isUserCancelledError, ToolkitError } from '../../errors'
 import { openLaunchJsonFile } from './commands/addSamDebugConfiguration'
 import { Logging } from '../../logger/commands'
@@ -471,8 +472,8 @@ export class SamDebugConfigProvider implements vscode.DebugConfigurationProvider
         }
 
         const isZip = CloudFormation.isZipLambdaResource(templateResource?.Properties)
-        const runtime: string | undefined =
-            config.lambda?.runtime ??
+        const runtime: Runtime | undefined =
+            (config.lambda?.runtime as Runtime) ??
             (template && isZip
                 ? CloudFormation.getStringForProperty(templateResource?.Properties, 'Runtime', template)
                 : undefined) ??
@@ -690,7 +691,7 @@ export class SamDebugConfigProvider implements vscode.DebugConfigurationProvider
     public async invokeConfig(config: SamLaunchRequestArgs): Promise<SamLaunchRequestArgs> {
         telemetry.record({
             debug: !config.noDebug,
-            runtime: config.runtime as Runtime,
+            runtime: config.runtime as TelemetryRuntime,
             lambdaArchitecture: config.architecture,
             lambdaPackageType: (await isImageLambdaConfig(config)) ? 'Image' : 'Zip',
             version: await getSamCliVersion(getSamCliContext()),
diff --git a/packages/core/src/shared/sam/debugger/pythonSamDebug.ts b/packages/core/src/shared/sam/debugger/pythonSamDebug.ts
index 670c2ddd71a..902dc85003d 100644
--- a/packages/core/src/shared/sam/debugger/pythonSamDebug.ts
+++ b/packages/core/src/shared/sam/debugger/pythonSamDebug.ts
@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { Runtime } from 'aws-sdk/clients/lambda'
+import { Runtime } from '@aws-sdk/client-lambda'
 import * as os from 'os'
 import * as path from 'path'
 import {
@@ -166,7 +166,7 @@ function getPythonExeAndBootstrap(runtime: Runtime) {
             return { python: '/var/lang/bin/python3.11', bootstrap: '/var/runtime/bootstrap.py' }
         case 'python3.12':
             return { python: '/var/lang/bin/python3.12', bootstrap: '/var/runtime/bootstrap.py' }
-        case 'python3.13':
+        case 'python3.13' as Runtime:
             return { python: '/var/lang/bin/python3.13', bootstrap: '/var/runtime/bootstrap.py' }
         default:
             throw new Error(`Python SAM debug logic ran for invalid Python runtime: ${runtime}`)
diff --git a/packages/core/src/shared/sam/localLambdaRunner.ts b/packages/core/src/shared/sam/localLambdaRunner.ts
index 6d28048be48..447fad81f26 100644
--- a/packages/core/src/shared/sam/localLambdaRunner.ts
+++ b/packages/core/src/shared/sam/localLambdaRunner.ts
@@ -32,6 +32,7 @@ import { SamCliError } from './cli/samCliInvokerUtils'
 import fs from '../fs/fs'
 import { getSpawnEnv } from '../env/resolveEnv'
 import { asEnvironmentVariables } from '../../auth/credentials/utils'
+import { Runtime } from '@aws-sdk/client-lambda'
 
 const localize = nls.loadMessageBundle()
 
@@ -247,7 +248,7 @@ async function invokeLambdaHandler(
             parameterOverrides: config.parameterOverrides,
             name: config.name,
             region: config.region,
-            runtime: config.lambda?.runtime,
+            runtime: config.lambda?.runtime as Runtime,
         }
 
         // sam local invoke ...
@@ -524,7 +525,7 @@ export async function waitForPort(port: number, timeout: Timeout, isDebugPort: b
     }
 }
 
-export function shouldAppendRelativePathToFuncHandler(runtime: string): boolean {
+export function shouldAppendRelativePathToFuncHandler(runtime: Runtime): boolean {
     // getFamily will throw an error if the runtime doesn't exist
     switch (getFamily(runtime)) {
         case RuntimeFamily.NodeJS:
diff --git a/packages/core/src/shared/sam/utils.ts b/packages/core/src/shared/sam/utils.ts
index ca2446fe3e9..51e93e80645 100644
--- a/packages/core/src/shared/sam/utils.ts
+++ b/packages/core/src/shared/sam/utils.ts
@@ -18,6 +18,7 @@ import { telemetry } from '../telemetry/telemetry'
 import globals from '../extensionGlobals'
 import { getLogger } from '../logger/logger'
 import { ChildProcessResult } from '../utilities/processUtils'
+import { Runtime } from '@aws-sdk/client-lambda'
 
 /**
  * @description determines the root directory of the project given Template Item
@@ -66,7 +67,7 @@ export async function isDotnetRuntime(templateUri: vscode.Uri, contents?: string
             }
         }
     }
-    const globalRuntime = samTemplate.template.Globals?.Function?.Runtime as string
+    const globalRuntime = samTemplate.template.Globals?.Function?.Runtime as Runtime
     return globalRuntime ? getFamily(globalRuntime) === RuntimeFamily.DotNet : false
 }
 
diff --git a/packages/core/src/shared/ui/sam/stackPrompter.ts b/packages/core/src/shared/ui/sam/stackPrompter.ts
index be1350489c5..3e86dc08859 100644
--- a/packages/core/src/shared/ui/sam/stackPrompter.ts
+++ b/packages/core/src/shared/ui/sam/stackPrompter.ts
@@ -2,7 +2,7 @@
  * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
-import { StackSummary } from 'aws-sdk/clients/cloudformation'
+import { StackSummary } from '@aws-sdk/client-cloudformation'
 import { getAwsConsoleUrl } from '../../awsConsole'
 import { CloudFormationClient } from '../../clients/cloudFormation'
 import * as vscode from 'vscode'
@@ -13,9 +13,10 @@ import { getRecentResponse } from '../../sam/utils'
 
 export const localize = nls.loadMessageBundle()
 
-const canPickStack = (s: StackSummary) => s.StackStatus.endsWith('_COMPLETE')
+const canPickStack = (s: StackSummary) => s.StackStatus?.endsWith('_COMPLETE')
 const canShowStack = (s: StackSummary) =>
-    (s.StackStatus.endsWith('_COMPLETE') || s.StackStatus.endsWith('_IN_PROGRESS')) && !s.StackStatus.includes('DELETE')
+    (s.StackStatus?.endsWith('_COMPLETE') || s.StackStatus?.endsWith('_IN_PROGRESS')) &&
+    !s.StackStatus.includes('DELETE')
 
 /**
  * Creates a quick pick prompter for choosing a CloudFormation stack
diff --git a/packages/core/src/test/awsService/appBuilder/lambda2sam/lambda2samCoreLogic.test.ts b/packages/core/src/test/awsService/appBuilder/lambda2sam/lambda2samCoreLogic.test.ts
index 05a5aad9ed4..c618dac2197 100644
--- a/packages/core/src/test/awsService/appBuilder/lambda2sam/lambda2samCoreLogic.test.ts
+++ b/packages/core/src/test/awsService/appBuilder/lambda2sam/lambda2samCoreLogic.test.ts
@@ -19,7 +19,7 @@ import { ToolkitError } from '../../../../shared/errors'
 import os from 'os'
 import path from 'path'
 import { LAMBDA_FUNCTION_TYPE } from '../../../../shared/cloudformation/cloudformation'
-import { ResourcesToImport } from 'aws-sdk/clients/cloudformation'
+import { ResourceToImport } from '@aws-sdk/client-cloudformation'
 
 describe('lambda2samCoreLogic', function () {
     let sandbox: sinon.SinonSandbox
@@ -422,7 +422,7 @@ describe('lambda2samCoreLogic', function () {
             // Setup Lambda node
             const lambdaNode = mockLambdaNode()
 
-            const resourceToImport: ResourcesToImport = [
+            const resourceToImport: ResourceToImport[] = [
                 {
                     ResourceType: LAMBDA_FUNCTION_TYPE,
                     LogicalResourceId: 'TestFunc',
@@ -470,7 +470,7 @@ describe('lambda2samCoreLogic', function () {
             // Make createChangeSet fail
             cfnClientStub.createChangeSet.resolves({}) // No Id
 
-            const resourceToImport: ResourcesToImport = [
+            const resourceToImport: ResourceToImport[] = [
                 {
                     ResourceType: LAMBDA_FUNCTION_TYPE,
                     LogicalResourceId: 'TestFunc',
diff --git a/packages/core/src/test/awsService/appBuilder/utils.test.ts b/packages/core/src/test/awsService/appBuilder/utils.test.ts
index eaaa69254d7..08edd14f47c 100644
--- a/packages/core/src/test/awsService/appBuilder/utils.test.ts
+++ b/packages/core/src/test/awsService/appBuilder/utils.test.ts
@@ -26,9 +26,11 @@ import { assertTextEditorContains } from '../../testUtil'
 import { DefaultLambdaClient } from '../../../shared/clients/lambdaClient'
 import { ToolkitError } from '../../../shared/errors'
 import globals from '../../../shared/extensionGlobals'
+import { Runtime } from '@aws-sdk/client-lambda'
+import { CloudFormationClient } from '@aws-sdk/client-cloudformation'
 
 interface TestScenario {
-    runtime: string
+    runtime: Runtime
     handler: string
     codeUri: string
     fileLocation: string
@@ -505,7 +507,7 @@ describe('AppBuilder Utils', function () {
                 mockLambdaClient.invoke.rejects(permissionError)
 
                 try {
-                    await enhancedClient.invoke('test-function', '{}')
+                    await enhancedClient.invoke('test-function', new TextEncoder().encode('{}'))
                     assert.fail('Expected error to be thrown')
                 } catch (error) {
                     assert(error instanceof ToolkitError)
@@ -571,19 +573,13 @@ describe('AppBuilder Utils', function () {
         })
 
         describe('EnhancedCloudFormationClient', function () {
-            let mockCfnClient: any
+            let mockCfnClient: sinon.SinonStubbedInstance<CloudFormationClient>
             let enhancedClient: EnhancedCloudFormationClient
 
             beforeEach(function () {
                 // Create a mock CloudFormation client with all required methods
-                mockCfnClient = {
-                    describeStacks: sandbox.stub(),
-                    getTemplate: sandbox.stub(),
-                    createChangeSet: sandbox.stub(),
-                    describeStackResource: sandbox.stub(),
-                    describeStackResources: sandbox.stub(),
-                }
-                enhancedClient = new EnhancedCloudFormationClient(mockCfnClient, 'us-east-1')
+                mockCfnClient = sandbox.createStubInstance(CloudFormationClient)
+                enhancedClient = new EnhancedCloudFormationClient(mockCfnClient as any, 'us-east-1')
             })
 
             it('should enhance permission errors for describeStacks', async function () {
@@ -592,9 +588,7 @@ describe('AppBuilder Utils', function () {
                     time: new Date(),
                     statusCode: 403,
                 })
-                mockCfnClient.describeStacks.returns({
-                    promise: sandbox.stub().rejects(permissionError),
-                } as any)
+                mockCfnClient.send.rejects(permissionError)
 
                 try {
                     await enhancedClient.describeStacks({ StackName: 'test-stack' })
@@ -619,9 +613,7 @@ describe('AppBuilder Utils', function () {
                     time: new Date(),
                     statusCode: 403,
                 })
-                mockCfnClient.getTemplate.returns({
-                    promise: sandbox.stub().rejects(permissionError),
-                } as any)
+                mockCfnClient.send.rejects(permissionError)
 
                 try {
                     await enhancedClient.getTemplate({ StackName: 'test-stack' })
@@ -644,9 +636,7 @@ describe('AppBuilder Utils', function () {
                     time: new Date(),
                     statusCode: 403,
                 })
-                mockCfnClient.createChangeSet.returns({
-                    promise: sandbox.stub().rejects(permissionError),
-                } as any)
+                mockCfnClient.send.rejects(permissionError)
 
                 try {
                     await enhancedClient.createChangeSet({
@@ -673,9 +663,7 @@ describe('AppBuilder Utils', function () {
                     time: new Date(),
                     statusCode: 403,
                 })
-                mockCfnClient.describeStackResource.returns({
-                    promise: sandbox.stub().rejects(permissionError),
-                } as any)
+                mockCfnClient.send.rejects(permissionError)
 
                 try {
                     await enhancedClient.describeStackResource({
@@ -701,9 +689,7 @@ describe('AppBuilder Utils', function () {
                     time: new Date(),
                     statusCode: 403,
                 })
-                mockCfnClient.describeStackResources.returns({
-                    promise: sandbox.stub().rejects(permissionError),
-                } as any)
+                mockCfnClient.send.rejects(permissionError)
 
                 try {
                     await enhancedClient.describeStackResources({ StackName: 'test-stack' })
@@ -722,9 +708,7 @@ describe('AppBuilder Utils', function () {
 
             it('should pass through non-permission errors', async function () {
                 const nonPermissionError = new Error('Stack not found')
-                mockCfnClient.describeStacks.returns({
-                    promise: sandbox.stub().rejects(nonPermissionError),
-                } as any)
+                mockCfnClient.send.rejects(nonPermissionError)
 
                 try {
                     await enhancedClient.describeStacks({ StackName: 'test-stack' })
@@ -736,9 +720,7 @@ describe('AppBuilder Utils', function () {
 
             it('should return successful results when no errors occur', async function () {
                 const mockResponse = { Stacks: [{ StackName: 'test-stack' }] }
-                mockCfnClient.describeStacks.returns({
-                    promise: sandbox.stub().resolves(mockResponse),
-                } as any)
+                mockCfnClient.send.resolves(mockResponse)
 
                 const result = await enhancedClient.describeStacks({ StackName: 'test-stack' })
                 assert.strictEqual(result, mockResponse)
@@ -748,7 +730,7 @@ describe('AppBuilder Utils', function () {
         describe('Client Factory Functions', function () {
             beforeEach(function () {
                 // Stub the global SDK client builder
-                sandbox.stub(globals.sdkClientBuilder, 'createAwsService').resolves({} as any)
+                sandbox.stub(globals.sdkClientBuilderV3, 'createAwsService').resolves({} as any)
             })
 
             it('should return EnhancedLambdaClient from getLambdaClient', function () {
diff --git a/packages/core/src/test/eventSchemas/model/schemaCodeLangs.test.ts b/packages/core/src/test/eventSchemas/model/schemaCodeLangs.test.ts
index 619f7bd035e..6c023a52676 100644
--- a/packages/core/src/test/eventSchemas/model/schemaCodeLangs.test.ts
+++ b/packages/core/src/test/eventSchemas/model/schemaCodeLangs.test.ts
@@ -10,6 +10,7 @@ import {
     schemaCodeLangs,
 } from '../../../eventSchemas/models/schemaCodeLangs'
 import { samZipLambdaRuntimes } from '../../../lambda/models/samLambdaRuntime'
+import { Runtime } from '@aws-sdk/client-lambda'
 
 describe('getLanguageDetails', function () {
     it('should successfully return details for supported languages', function () {
@@ -32,7 +33,7 @@ describe('getApiValueForSchemasDownload', function () {
                 case 'python3.9':
                 case 'python3.11':
                 case 'python3.12':
-                case 'python3.13':
+                case 'python3.13' as Runtime:
                 case 'python3.10': {
                     const result = getApiValueForSchemasDownload(runtime)
                     assert.strictEqual(result, 'Python36', 'Api value used by schemas api')
diff --git a/packages/core/src/test/lambda/commands/copyLambdaUrl.test.ts b/packages/core/src/test/lambda/commands/copyLambdaUrl.test.ts
index e55267182a3..acd3b98f052 100644
--- a/packages/core/src/test/lambda/commands/copyLambdaUrl.test.ts
+++ b/packages/core/src/test/lambda/commands/copyLambdaUrl.test.ts
@@ -10,7 +10,7 @@ import { LambdaFunctionNode } from '../../../lambda/explorer/lambdaFunctionNode'
 import { DefaultLambdaClient, LambdaClient } from '../../../shared/clients/lambdaClient'
 import { addCodiconToString } from '../../../shared/utilities/textUtilities'
 import { env } from 'vscode'
-import { FunctionUrlConfig } from 'aws-sdk/clients/lambda'
+import { FunctionUrlConfig } from '@aws-sdk/client-lambda'
 import { createQuickPickPrompterTester } from '../../shared/ui/testUtils'
 import { getTestWindow } from '../../shared/vscode/window'
 
@@ -22,11 +22,11 @@ import { getTestWindow } from '../../shared/vscode/window'
  */
 export function buildFunctionUrlConfig(options: Partial<FunctionUrlConfig>): FunctionUrlConfig {
     return {
-        AuthType: options.AuthType ?? '',
-        CreationTime: options.CreationTime ?? '',
-        FunctionArn: options.FunctionArn ?? '',
-        FunctionUrl: options.FunctionUrl ?? '',
-        LastModifiedTime: options.LastModifiedTime ?? '',
+        AuthType: options.AuthType,
+        CreationTime: options.CreationTime,
+        FunctionArn: options.FunctionArn,
+        FunctionUrl: options.FunctionUrl,
+        LastModifiedTime: options.LastModifiedTime,
     }
 }
 
@@ -94,10 +94,10 @@ describe('lambda func url prompter', async () => {
         const tester = createQuickPickPrompterTester(prompter)
         tester.assertItems(
             configList.map((c) => {
-                return { label: c.FunctionArn, data: c.FunctionUrl } // order matters
+                return { label: c.FunctionArn!, data: c.FunctionUrl } // order matters
             })
         )
-        tester.acceptItem(configList[1].FunctionArn)
+        tester.acceptItem(configList[1].FunctionArn!)
         await tester.result(configList[1].FunctionUrl)
     })
 })
diff --git a/packages/core/src/test/lambda/commands/createNewSamApp.test.ts b/packages/core/src/test/lambda/commands/createNewSamApp.test.ts
index 8bb25119301..c31f922483c 100644
--- a/packages/core/src/test/lambda/commands/createNewSamApp.test.ts
+++ b/packages/core/src/test/lambda/commands/createNewSamApp.test.ts
@@ -26,7 +26,7 @@ import {
 import { normalize } from '../../../shared/utilities/pathUtils'
 import { getIdeProperties, isCloud9 } from '../../../shared/extensionUtilities'
 import globals from '../../../shared/extensionGlobals'
-import { Runtime } from '../../../shared/telemetry/telemetry'
+import { Runtime } from '@aws-sdk/client-lambda'
 import { stub } from '../../utilities/stubber'
 import sinon from 'sinon'
 import { fs } from '../../../shared'
diff --git a/packages/core/src/test/lambda/local/debugConfiguration.test.ts b/packages/core/src/test/lambda/local/debugConfiguration.test.ts
index 12192127eeb..0a0aab0dc99 100644
--- a/packages/core/src/test/lambda/local/debugConfiguration.test.ts
+++ b/packages/core/src/test/lambda/local/debugConfiguration.test.ts
@@ -18,7 +18,7 @@ import { CloudFormationTemplateRegistry } from '../../../shared/fs/templateRegis
 import { getArchitecture, isImageLambdaConfig } from '../../../lambda/local/debugConfiguration'
 import * as CloudFormation from '../../../shared/cloudformation/cloudformation'
 import globals from '../../../shared/extensionGlobals'
-import { Runtime } from '../../../shared/telemetry/telemetry'
+import { Runtime } from '@aws-sdk/client-lambda'
 import { fs } from '../../../shared'
 
 describe('makeCoreCLRDebugConfiguration', function () {
diff --git a/packages/core/src/test/lambda/models/samLambdaRuntime.test.ts b/packages/core/src/test/lambda/models/samLambdaRuntime.test.ts
index f47cc3fe06b..566c465a0dd 100644
--- a/packages/core/src/test/lambda/models/samLambdaRuntime.test.ts
+++ b/packages/core/src/test/lambda/models/samLambdaRuntime.test.ts
@@ -4,7 +4,6 @@
  */
 
 import assert from 'assert'
-import { Runtime } from 'aws-sdk/clients/lambda'
 import {
     compareSamLambdaRuntime,
     getDependencyManager,
@@ -16,11 +15,12 @@ import {
     getNodeMajorVersion,
     nodeJsRuntimes,
 } from '../../../lambda/models/samLambdaRuntime'
+import { Runtime } from '@aws-sdk/client-lambda'
 
 describe('compareSamLambdaRuntime', async function () {
     const scenarios: {
-        lowerRuntime: Runtime
-        higherRuntime: Runtime
+        lowerRuntime: string
+        higherRuntime: string
     }[] = [
         { lowerRuntime: 'nodejs14.x', higherRuntime: 'nodejs16.x' },
         { lowerRuntime: 'nodejs16.x', higherRuntime: 'nodejs16.x (Image)' },
@@ -48,13 +48,13 @@ describe('getDependencyManager', function () {
         assert.throws(() => getDependencyManager('nodejs'))
     })
     it('throws on unknown runtimes', function () {
-        assert.throws(() => getDependencyManager('BASIC'))
+        assert.throws(() => getDependencyManager('BASIC' as Runtime))
     })
 })
 
 describe('getFamily', function () {
     it('unknown runtime name', function () {
-        assert.strictEqual(getFamily('foo'), RuntimeFamily.Unknown)
+        assert.strictEqual(getFamily('foo' as Runtime), RuntimeFamily.Unknown)
     })
     it('handles all known runtimes', function () {
         for (const runtime of samZipLambdaRuntimes) {
diff --git a/packages/core/src/test/lambda/models/samTemplates.test.ts b/packages/core/src/test/lambda/models/samTemplates.test.ts
index 4abb3f87315..7fe78e630c8 100644
--- a/packages/core/src/test/lambda/models/samTemplates.test.ts
+++ b/packages/core/src/test/lambda/models/samTemplates.test.ts
@@ -20,6 +20,7 @@ import {
 import { Set } from 'immutable'
 
 import { samZipLambdaRuntimes } from '../../../lambda/models/samLambdaRuntime'
+import { Runtime } from '@aws-sdk/client-lambda'
 
 let validTemplateOptions: Set<SamTemplate>
 let validPythonTemplateOptions: Set<SamTemplate>
@@ -66,7 +67,7 @@ describe('getSamTemplateWizardOption', function () {
                 case 'python3.10':
                 case 'python3.11':
                 case 'python3.12':
-                case 'python3.13':
+                case 'python3.13' as Runtime:
                     assert.deepStrictEqual(
                         result,
                         validPythonTemplateOptions,
diff --git a/packages/core/src/test/lambda/remoteDebugging/ldkClient.test.ts b/packages/core/src/test/lambda/remoteDebugging/ldkClient.test.ts
index 24c9b956e70..c91be446753 100644
--- a/packages/core/src/test/lambda/remoteDebugging/ldkClient.test.ts
+++ b/packages/core/src/test/lambda/remoteDebugging/ldkClient.test.ts
@@ -5,7 +5,7 @@
 
 import assert from 'assert'
 import sinon from 'sinon'
-import { Lambda } from 'aws-sdk'
+import { FunctionConfiguration } from '@aws-sdk/client-lambda'
 import { LdkClient, getRegionFromArn, isTunnelInfo } from '../../../lambda/remoteDebugging/ldkClient'
 import { LocalProxy } from '../../../lambda/remoteDebugging/localProxy'
 import * as utils from '../../../lambda/remoteDebugging/utils'
@@ -191,7 +191,7 @@ describe('LdkClient', () => {
     })
 
     describe('getFunctionDetail()', () => {
-        const mockFunctionConfig: Lambda.FunctionConfiguration = createMockFunctionConfig({
+        const mockFunctionConfig: FunctionConfiguration = createMockFunctionConfig({
             FunctionArn: 'arn:aws:lambda:us-east-1:123456789012:function:testFunction',
         })
 
@@ -220,7 +220,7 @@ describe('LdkClient', () => {
     })
 
     describe('createDebugDeployment()', () => {
-        const mockFunctionConfig: Lambda.FunctionConfiguration = createMockFunctionConfig({
+        const mockFunctionConfig: FunctionConfiguration = createMockFunctionConfig({
             FunctionArn: 'arn:aws:lambda:us-east-1:123456789012:function:testFunction',
         })
 
@@ -299,7 +299,7 @@ describe('LdkClient', () => {
     })
 
     describe('removeDebugDeployment()', () => {
-        const mockFunctionConfig: Lambda.FunctionConfiguration = createMockFunctionConfig({
+        const mockFunctionConfig: FunctionConfiguration = createMockFunctionConfig({
             FunctionArn: 'arn:aws:lambda:us-east-1:123456789012:function:testFunction',
         })
 
diff --git a/packages/core/src/test/lambda/remoteDebugging/ldkController.test.ts b/packages/core/src/test/lambda/remoteDebugging/ldkController.test.ts
index fe4062bf673..525f8ad80f3 100644
--- a/packages/core/src/test/lambda/remoteDebugging/ldkController.test.ts
+++ b/packages/core/src/test/lambda/remoteDebugging/ldkController.test.ts
@@ -6,7 +6,7 @@
 import assert from 'assert'
 import * as vscode from 'vscode'
 import sinon, { SinonStubbedInstance, createStubInstance } from 'sinon'
-import { Lambda } from 'aws-sdk'
+import { FunctionConfiguration } from '@aws-sdk/client-lambda'
 import {
     RemoteDebugController,
     activateRemoteDebugging,
@@ -200,7 +200,7 @@ describe('RemoteDebugController', () => {
 
     describe('Debug Session Management', () => {
         let mockConfig: DebugConfig
-        let mockFunctionConfig: Lambda.FunctionConfiguration
+        let mockFunctionConfig: FunctionConfiguration
 
         beforeEach(() => {
             mockConfig = createMockDebugConfig({
@@ -406,7 +406,7 @@ describe('RemoteDebugController', () => {
 
     describe('Telemetry Verification', () => {
         let mockConfig: DebugConfig
-        let mockFunctionConfig: Lambda.FunctionConfiguration
+        let mockFunctionConfig: FunctionConfiguration
 
         beforeEach(() => {
             mockConfig = createMockDebugConfig({
diff --git a/packages/core/src/test/lambda/remoteDebugging/localStackLambdaDebugger.test.ts b/packages/core/src/test/lambda/remoteDebugging/localStackLambdaDebugger.test.ts
index 46448cbbc08..d91fc150f71 100644
--- a/packages/core/src/test/lambda/remoteDebugging/localStackLambdaDebugger.test.ts
+++ b/packages/core/src/test/lambda/remoteDebugging/localStackLambdaDebugger.test.ts
@@ -18,7 +18,7 @@ import {
     setupMockVSCodeDebugAPIs,
 } from './testUtils'
 import { DebugConfig } from '../../../lambda/remoteDebugging/lambdaDebugger'
-import { Lambda } from 'aws-sdk'
+import { FunctionConfiguration, Runtime } from '@aws-sdk/client-lambda'
 import { assertTelemetry } from '../../testUtil'
 import * as remoteDebuggingUtils from '../../../lambda/remoteDebugging/utils'
 import { DefaultLambdaClient } from '../../../shared/clients/lambdaClient'
@@ -31,7 +31,7 @@ describe('RemoteDebugController with LocalStackLambdaDebugger', () => {
     let controller: RemoteDebugController
     let mockGlobalState: any
     let mockConfig: DebugConfig
-    let mockFunctionConfig: Lambda.FunctionConfiguration
+    let mockFunctionConfig: FunctionConfiguration
     let fetchStub: sinon.SinonStub
 
     beforeEach(() => {
@@ -60,7 +60,7 @@ describe('RemoteDebugController with LocalStackLambdaDebugger', () => {
             layerArn: undefined,
             lambdaTimeout: undefined,
         })
-        mockFunctionConfig = createMockFunctionConfig({ Runtime: 'nodejs22.x' })
+        mockFunctionConfig = createMockFunctionConfig({ Runtime: 'nodejs22.x' as Runtime })
     })
 
     afterEach(() => {
diff --git a/packages/core/src/test/lambda/remoteDebugging/testUtils.ts b/packages/core/src/test/lambda/remoteDebugging/testUtils.ts
index 03aec290426..42deaa4ec96 100644
--- a/packages/core/src/test/lambda/remoteDebugging/testUtils.ts
+++ b/packages/core/src/test/lambda/remoteDebugging/testUtils.ts
@@ -4,7 +4,7 @@
  */
 
 import sinon from 'sinon'
-import { Lambda } from 'aws-sdk'
+import { Architecture, FunctionConfiguration, Runtime, SnapStartApplyOn } from '@aws-sdk/client-lambda'
 import { LambdaFunctionNode } from '../../../lambda/explorer/lambdaFunctionNode'
 import { InitialData } from '../../../lambda/vue/remoteInvoke/invokeLambda'
 import type { DebugConfig } from '../../../lambda/remoteDebugging/lambdaDebugger'
@@ -12,19 +12,17 @@ import type { DebugConfig } from '../../../lambda/remoteDebugging/lambdaDebugger
 /**
  * Creates a mock Lambda function configuration for testing
  */
-export function createMockFunctionConfig(
-    overrides: Partial<Lambda.FunctionConfiguration> = {}
-): Lambda.FunctionConfiguration {
+export function createMockFunctionConfig(overrides: Partial<FunctionConfiguration> = {}): FunctionConfiguration {
     return {
         FunctionName: 'testFunction',
         FunctionArn: 'arn:aws:lambda:us-west-2:123456789012:function:testFunction',
-        Runtime: 'nodejs18.x',
+        Runtime: Runtime.nodejs18x,
         Handler: 'index.handler',
         Timeout: 30,
         Layers: [],
         Environment: { Variables: {} },
-        Architectures: ['x86_64'],
-        SnapStart: { ApplyOn: 'None' },
+        Architectures: [Architecture.x86_64],
+        SnapStart: { ApplyOn: SnapStartApplyOn.None },
         ...overrides,
     }
 }
diff --git a/packages/core/src/test/lambda/utils.test.ts b/packages/core/src/test/lambda/utils.test.ts
index a3eebe043a7..7a8e82043cf 100644
--- a/packages/core/src/test/lambda/utils.test.ts
+++ b/packages/core/src/test/lambda/utils.test.ts
@@ -18,6 +18,7 @@ import { DefaultLambdaClient } from '../../shared/clients/lambdaClient'
 import { fs } from '../../shared/fs/fs'
 import { tempDirPath } from '../../shared/filesystemUtilities'
 import path from 'path'
+import { Runtime } from '@aws-sdk/client-lambda'
 
 describe('lambda utils', function () {
     const mockLambda = {
@@ -67,7 +68,7 @@ describe('lambda utils', function () {
                 })
             )
             // runtime that isn't present, period
-            assert.throws(() => getLambdaDetails({ Runtime: 'COBOL-60', Handler: 'asdf.asdf' }))
+            assert.throws(() => getLambdaDetails({ Runtime: 'COBOL-60' as Runtime, Handler: 'asdf.asdf' }))
         })
     })
 
diff --git a/packages/core/src/test/lambda/vue/remoteInvoke/invokeLambda.test.ts b/packages/core/src/test/lambda/vue/remoteInvoke/invokeLambda.test.ts
index e04f017acfb..90f448e750e 100644
--- a/packages/core/src/test/lambda/vue/remoteInvoke/invokeLambda.test.ts
+++ b/packages/core/src/test/lambda/vue/remoteInvoke/invokeLambda.test.ts
@@ -22,6 +22,7 @@ import * as samCliRemoteTestEvent from '../../../../shared/sam/cli/samCliRemoteT
 import { TestEventsOperation, SamCliRemoteTestEventsParameters } from '../../../../shared/sam/cli/samCliRemoteTestEvent'
 import { assertLogsContain } from '../../../globalSetup.test'
 import { createResponse } from '../../../testUtil'
+import { InvocationResponse } from '@aws-sdk/client-lambda'
 
 describe('RemoteInvokeWebview', () => {
     let outputChannel: vscode.OutputChannel
@@ -61,8 +62,8 @@ describe('RemoteInvokeWebview', () => {
             const input = '{"key": "value"}'
             const mockResponse = {
                 LogResult: Buffer.from('Test log').toString('base64'),
-                Payload: '{"result": "success"}',
-            }
+                Payload: new TextEncoder().encode('{"result": "success"}'),
+            } satisfies InvocationResponse
             client.invoke.resolves(mockResponse)
 
             const appendedLines: string[] = []
@@ -87,8 +88,8 @@ describe('RemoteInvokeWebview', () => {
         it('handles Lambda invocation with no payload', async () => {
             const mockResponse = {
                 LogResult: Buffer.from('Test log').toString('base64'),
-                Payload: '',
-            }
+                Payload: new TextEncoder().encode(''),
+            } satisfies InvocationResponse
 
             client.invoke.resolves(mockResponse)
             const appendedLines: string[] = []
@@ -111,8 +112,8 @@ describe('RemoteInvokeWebview', () => {
         })
         it('handles Lambda invocation with undefined LogResult', async () => {
             const mockResponse = {
-                Payload: '{"result": "success"}',
-            }
+                Payload: new TextEncoder().encode('{"result": "success"}'),
+            } satisfies InvocationResponse
 
             client.invoke.resolves(mockResponse)
 
diff --git a/packages/core/src/test/lambda/vue/remoteInvoke/invokeLambdaDebugging.test.ts b/packages/core/src/test/lambda/vue/remoteInvoke/invokeLambdaDebugging.test.ts
index 2d48d0cf0d8..f08bf474de8 100644
--- a/packages/core/src/test/lambda/vue/remoteInvoke/invokeLambdaDebugging.test.ts
+++ b/packages/core/src/test/lambda/vue/remoteInvoke/invokeLambdaDebugging.test.ts
@@ -20,6 +20,7 @@ import globals from '../../../../shared/extensionGlobals'
 import fs from '../../../../shared/fs/fs'
 import { ToolkitError } from '../../../../shared'
 import { createMockDebugConfig } from '../../remoteDebugging/testUtils'
+import { InvocationResponse } from '@aws-sdk/client-lambda'
 
 describe('RemoteInvokeWebview - Debugging Functionality', () => {
     let outputChannel: vscode.OutputChannel
@@ -394,8 +395,8 @@ describe('RemoteInvokeWebview - Debugging Functionality', () => {
         it('should invoke lambda with remote debugging enabled', async () => {
             const mockResponse = {
                 LogResult: Buffer.from('Debug log').toString('base64'),
-                Payload: '{"result": "debug success"}',
-            }
+                Payload: new TextEncoder().encode('{"result": "debug success"}'),
+            } satisfies InvocationResponse
             client.invoke.resolves(mockResponse)
             mockDebugController.isDebugging = true
             mockDebugController.qualifier = 'v1'
@@ -411,8 +412,8 @@ describe('RemoteInvokeWebview - Debugging Functionality', () => {
         it('should handle timer management during debugging invocation', async () => {
             const mockResponse = {
                 LogResult: Buffer.from('Debug log').toString('base64'),
-                Payload: '{"result": "debug success"}',
-            }
+                Payload: new TextEncoder().encode('{"result": "debug success"}'),
+            } satisfies InvocationResponse
             client.invoke.resolves(mockResponse)
             mockDebugController.isDebugging = true
 
@@ -520,8 +521,8 @@ describe('RemoteInvokeWebview - Debugging Functionality', () => {
             // 2. Test lambda invocation during debugging
             const mockResponse = {
                 LogResult: Buffer.from('Debug invocation log').toString('base64'),
-                Payload: '{"debugResult": "success"}',
-            }
+                Payload: new TextEncoder().encode('{"debugResult": "success"}'),
+            } satisfies InvocationResponse
             client.invoke.resolves(mockResponse)
 
             await remoteInvokeWebview.invokeLambda('{"debugInput": "test"}', 'integration-test', true)
@@ -581,8 +582,8 @@ describe('RemoteInvokeWebview - Debugging Functionality', () => {
             // Test invocation with version qualifier
             const mockResponse = {
                 LogResult: Buffer.from('Version debug log').toString('base64'),
-                Payload: '{"versionResult": "success"}',
-            }
+                Payload: new TextEncoder().encode('{"versionResult": "success"}'),
+            } satisfies InvocationResponse
             client.invoke.resolves(mockResponse)
 
             await remoteInvokeWebview.invokeLambda('{"versionInput": "test"}', 'version-test', true)
diff --git a/packages/core/src/test/lambda/vue/remoteInvoke/remoteInvoke.test.ts b/packages/core/src/test/lambda/vue/remoteInvoke/remoteInvoke.test.ts
index 0fc94674c1e..852ba43d5bd 100644
--- a/packages/core/src/test/lambda/vue/remoteInvoke/remoteInvoke.test.ts
+++ b/packages/core/src/test/lambda/vue/remoteInvoke/remoteInvoke.test.ts
@@ -8,7 +8,7 @@ import * as vscode from 'vscode'
 import * as samCliRemoteTestEvent from '../../../../shared/sam/cli/samCliRemoteTestEvent'
 import { TestEventsOperation } from '../../../../shared/sam/cli/samCliRemoteTestEvent'
 import sinon, { SinonStubbedInstance, createStubInstance } from 'sinon'
-import { Lambda } from 'aws-sdk'
+import { InvocationResponse } from '@aws-sdk/client-lambda'
 
 // Tests to check that the internal integration between the functions operates correctly
 
@@ -31,10 +31,10 @@ describe('RemoteInvokeWebview', function () {
     describe('Invoke Remote Lambda Function with Payload', () => {
         it('should invoke with a simple payload', async function () {
             const input = '{"key": "value"}'
-            const mockResponse: Lambda.InvocationResponse = {
+            const mockResponse = {
                 LogResult: Buffer.from('Test log').toString('base64'),
-                Payload: '{"result": "success"}',
-            }
+                Payload: new TextEncoder().encode('{"result": "success"}'),
+            } satisfies InvocationResponse
             client.invoke.resolves(mockResponse)
             await remoteInvokeWebview.invokeLambda(input)
             sinon.assert.calledOnce(client.invoke)
diff --git a/packages/core/src/test/shared/activationReloadState.test.ts b/packages/core/src/test/shared/activationReloadState.test.ts
index d7ef8864adc..2dd0ba35bbd 100644
--- a/packages/core/src/test/shared/activationReloadState.test.ts
+++ b/packages/core/src/test/shared/activationReloadState.test.ts
@@ -8,6 +8,7 @@
 import assert from 'assert'
 import { ActivationReloadState } from '../../shared/activationReloadState'
 import globals, { checkDidReload } from '../../shared/extensionGlobals'
+import { Runtime } from '@aws-sdk/client-lambda'
 
 describe('ActivationReloadState', async function () {
     const activationReloadState = new ActivationReloadState()
@@ -64,7 +65,7 @@ describe('ActivationReloadState', async function () {
             activationReloadState.setSamInitState({
                 template: 'sometemplate',
                 readme: 'somepath',
-                runtime: 'someruntime',
+                runtime: 'someruntime' as Runtime,
                 isImage: false,
                 architecture: 'arm64',
             })
@@ -95,7 +96,7 @@ describe('ActivationReloadState', async function () {
             activationReloadState.setSamInitState({
                 template: 'sometemplate',
                 readme: 'somepath',
-                runtime: 'someruntime',
+                runtime: 'someruntime' as Runtime,
                 isImage: true,
                 architecture: 'arm64',
             })
@@ -211,7 +212,7 @@ describe('ActivationReloadState', async function () {
         activationReloadState.setSamInitState({
             template: 'sometemplate',
             readme: 'somepath',
-            runtime: 'someruntime',
+            runtime: 'someruntime' as Runtime,
             isImage: true,
             architecture: 'x86_64',
         })
diff --git a/packages/core/src/test/shared/applicationBuilder/explorer/nodes/deployedNode.test.ts b/packages/core/src/test/shared/applicationBuilder/explorer/nodes/deployedNode.test.ts
index 0191fb3b60b..3edd66ab5d4 100644
--- a/packages/core/src/test/shared/applicationBuilder/explorer/nodes/deployedNode.test.ts
+++ b/packages/core/src/test/shared/applicationBuilder/explorer/nodes/deployedNode.test.ts
@@ -26,6 +26,7 @@ import { Any } from '../../../../../shared/utilities/typeConstructors'
 import { IamConnection, ProfileMetadata } from '../../../../../auth/connection'
 import * as AuthUtils from '../../../../../auth/utils'
 import { assertLogsContain } from '../../../../../test/globalSetup.test'
+import { GetFunctionResponse } from '@aws-sdk/client-lambda'
 
 describe('DeployedResourceNode', () => {
     const expectedStackName = 'myStack'
@@ -171,7 +172,7 @@ describe('generateDeployedNode', () => {
                     FunctionArn: 'arn:aws:lambda:us-east-1:123456789012:function:my-project-lambda-function',
                     Runtime: 'python3.12',
                 },
-            } as AWS.Lambda.GetFunctionResponse
+            } as GetFunctionResponse
 
             mockDefaultLambdaClientInstance.getFunction.resolves(defaultLambdaClientGetFunctionResponse)
 
diff --git a/packages/core/src/test/shared/applicationBuilder/explorer/nodes/resourceNode.test.ts b/packages/core/src/test/shared/applicationBuilder/explorer/nodes/resourceNode.test.ts
index 42486ea267b..43a76c0fca3 100644
--- a/packages/core/src/test/shared/applicationBuilder/explorer/nodes/resourceNode.test.ts
+++ b/packages/core/src/test/shared/applicationBuilder/explorer/nodes/resourceNode.test.ts
@@ -34,7 +34,7 @@ describe('ResourceNode', () => {
                 Method: undefined,
             },
         ],
-    }
+    } satisfies ResourceTreeEntity
     const workspaceFolder = {
         uri: vscode.Uri.parse('myworkspace'),
         name: 'my-workspace',
diff --git a/packages/core/src/test/shared/sam/debugger/samDebugConfigProvider.test.ts b/packages/core/src/test/shared/sam/debugger/samDebugConfigProvider.test.ts
index 9fe7c76e842..f17c5a2cf22 100644
--- a/packages/core/src/test/shared/sam/debugger/samDebugConfigProvider.test.ts
+++ b/packages/core/src/test/shared/sam/debugger/samDebugConfigProvider.test.ts
@@ -2906,7 +2906,7 @@ describe('ensureRelativePaths', function () {
             undefined,
             'testName1',
             '/test1/project',
-            lambdaModel.getDefaultRuntime(lambdaModel.RuntimeFamily.NodeJS) ?? ''
+            lambdaModel.getDefaultRuntime(lambdaModel.RuntimeFamily.NodeJS)!
         )
         assert.strictEqual((codeConfig.invokeTarget as CodeTargetProperties).projectRoot, '/test1/project')
         ensureRelativePaths(workspace, codeConfig)
diff --git a/packages/core/src/testInteg/sam.test.ts b/packages/core/src/testInteg/sam.test.ts
index 8dd8b5cdb9b..38c84d992df 100644
--- a/packages/core/src/testInteg/sam.test.ts
+++ b/packages/core/src/testInteg/sam.test.ts
@@ -4,7 +4,7 @@
  */
 
 import assert from 'assert'
-import { Runtime } from 'aws-sdk/clients/lambda'
+import { Runtime } from '@aws-sdk/client-lambda'
 import { mkdtempSync } from 'fs' // eslint-disable-line no-restricted-imports
 import * as path from 'path'
 import * as semver from 'semver'
@@ -92,7 +92,7 @@ const dotnetDefaults = {
     vscodeMinimum: '1.80.0',
 }
 
-const defaults: Record<Runtime, TestScenarioDefaults> = {
+const defaults: Record<string, TestScenarioDefaults> = {
     nodejs: nodeDefaults,
     java: javaDefaults,
     python: pythonDefaults,
@@ -100,7 +100,7 @@ const defaults: Record<Runtime, TestScenarioDefaults> = {
 }
 
 function generateScenario(
-    runtime: Runtime,
+    runtime: string,
     version: string,
     options: Partial<TestScenario & { sourceTag: string }> = {},
     fromImage: boolean = false
@@ -110,7 +110,7 @@ function generateScenario(
     }
     const { sourceTag, ...defaultOverride } = options
     const source = `(${options.sourceTag ? `${options.sourceTag} ` : ''}${fromImage ? 'Image' : 'ZIP'})`
-    const fullName = `${runtime}${version}`
+    const fullName = `${runtime}${version}` as Runtime
     return {
         runtime: fullName,
         displayName: `${fullName} ${source}`,