diff --git a/src/aws-cpp-sdk-core/include/aws/core/client/AWSClientAsyncCRTP.h b/src/aws-cpp-sdk-core/include/aws/core/client/AWSClientAsyncCRTP.h
index fab268465b4..9c88573e197 100644
--- a/src/aws-cpp-sdk-core/include/aws/core/client/AWSClientAsyncCRTP.h
+++ b/src/aws-cpp-sdk-core/include/aws/core/client/AWSClientAsyncCRTP.h
@@ -97,7 +97,7 @@ namespace Client
             std::unique_lock<std::mutex> lock(pClient->m_shutdownMutex);
 
             pClient->m_isInitialized = false;
-
+            pClient->DisableRequestProcessing();
 
             if (timeoutMs == -1)
             {
@@ -107,10 +107,15 @@ namespace Client
                                       std::chrono::milliseconds(timeoutMs),
                                       [&](){ return pClient->m_operationsProcessed.load() == 0; });
 
-            pClient->m_endpointProvider.reset();
-            pClient->m_executor.reset();
+            if (pClient->m_operationsProcessed.load())
+            {
+                AWS_LOGSTREAM_FATAL(AwsServiceClientT::GetAllocationTag(), "Service client "
+                    << AwsServiceClientT::GetServiceName() << " is shutting down while async tasks are present.");
+            }
+
             pClient->m_clientConfiguration.executor.reset();
             pClient->m_clientConfiguration.retryStrategy.reset();
+            pClient->m_endpointProvider.reset();
         }
 
         /**
@@ -124,7 +129,7 @@ namespace Client
                          const std::shared_ptr<const Aws::Client::AsyncCallerContext>& context = nullptr) const
         {
             const AwsServiceClientT* clientThis = static_cast<const AwsServiceClientT*>(this);
-            Aws::Client::MakeAsyncOperation(operationFunc, clientThis, request, handler, context, clientThis->m_executor.get());
+            Aws::Client::MakeAsyncOperation(operationFunc, clientThis, request, handler, context, clientThis->m_clientConfiguration.executor.get());
         }
 
         /**
@@ -139,7 +144,7 @@ namespace Client
                          const std::shared_ptr<const Aws::Client::AsyncCallerContext>& context = nullptr) const
         {
             const AwsServiceClientT* clientThis = static_cast<const AwsServiceClientT*>(this);
-            Aws::Client::MakeAsyncStreamingOperation(operationFunc, clientThis, request, handler, context, clientThis->m_executor.get());
+            Aws::Client::MakeAsyncStreamingOperation(operationFunc, clientThis, request, handler, context, clientThis->m_clientConfiguration.executor.get());
         }
 
         /**
@@ -152,7 +157,7 @@ namespace Client
                          const std::shared_ptr<const Aws::Client::AsyncCallerContext>& context = nullptr) const
         {
             const AwsServiceClientT* clientThis = static_cast<const AwsServiceClientT*>(this);
-            Aws::Client::MakeAsyncOperation(operationFunc, clientThis, handler, context, clientThis->m_executor.get());
+            Aws::Client::MakeAsyncOperation(operationFunc, clientThis, handler, context, clientThis->m_clientConfiguration.executor.get());
         }
 
         /**
@@ -165,7 +170,7 @@ namespace Client
             -> std::future<decltype((static_cast<const AwsServiceClientT*>(nullptr)->*operationFunc)(request))>
         {
             const AwsServiceClientT* clientThis = static_cast<const AwsServiceClientT*>(this);
-            return Aws::Client::MakeCallableOperation(AwsServiceClientT::GetAllocationTag(), operationFunc, clientThis, request, clientThis->m_executor.get());
+            return Aws::Client::MakeCallableOperation(AwsServiceClientT::GetAllocationTag(), operationFunc, clientThis, request, clientThis->m_clientConfiguration.executor.get());
         }
 
         /**
@@ -178,7 +183,7 @@ namespace Client
             -> std::future<decltype((static_cast<const AwsServiceClientT*>(nullptr)->*operationFunc)(request))>
         {
             const AwsServiceClientT* clientThis = static_cast<const AwsServiceClientT*>(this);
-            return Aws::Client::MakeCallableStreamingOperation(AwsServiceClientT::GetAllocationTag(), operationFunc, clientThis, request, clientThis->m_executor.get());
+            return Aws::Client::MakeCallableStreamingOperation(AwsServiceClientT::GetAllocationTag(), operationFunc, clientThis, request, clientThis->m_clientConfiguration.executor.get());
         }
 
         /**
@@ -191,7 +196,7 @@ namespace Client
             -> std::future<decltype((static_cast<const AwsServiceClientT*>(nullptr)->*operationFunc)())>
         {
             const AwsServiceClientT* clientThis = static_cast<const AwsServiceClientT*>(this);
-            return Aws::Client::MakeCallableOperation(AwsServiceClientT::GetAllocationTag(), operationFunc, clientThis, clientThis->m_executor.get());
+            return Aws::Client::MakeCallableOperation(AwsServiceClientT::GetAllocationTag(), operationFunc, clientThis, clientThis->m_clientConfiguration.executor.get());
         }
     protected:
         std::atomic<bool> m_isInitialized;
diff --git a/src/aws-cpp-sdk-core/include/aws/core/client/ClientConfiguration.h b/src/aws-cpp-sdk-core/include/aws/core/client/ClientConfiguration.h
index a89a4cb3edb..de6ea12307e 100644
--- a/src/aws-cpp-sdk-core/include/aws/core/client/ClientConfiguration.h
+++ b/src/aws-cpp-sdk-core/include/aws/core/client/ClientConfiguration.h
@@ -14,7 +14,6 @@
 #include <aws/core/utils/Array.h>
 #include <aws/crt/Optional.h>
 #include <smithy/tracing/TelemetryProvider.h>
-#include <smithy/tracing/NoopTelemetryProvider.h>
 #include <memory>
 
 namespace Aws
@@ -69,12 +68,48 @@ namespace Aws
             bool shouldDisableIMDS = false;
         };
 
+        /**
+         * Utility struct to hold default factories used in ClientConfiguration.
+         */
+        struct AWS_CORE_API ClientConfigDefaultFactories
+        {
+            static std::shared_ptr<Aws::Utils::Threading::Executor> CreateExecutor();
+        };
+
         /**
          * This mutable structure is used to configure any of the AWS clients.
          * Default values can only be overwritten prior to passing to the client constructors.
          */
         struct AWS_CORE_API ClientConfiguration
         {
+            struct ProviderFactories
+            {
+                /**
+                 * Retry Strategy factory method. Default is DefaultRetryStrategy (i.e. exponential backoff).
+                 */
+                std::function<std::shared_ptr<RetryStrategy>()> retryStrategyCreateFn;
+                /**
+                 * Threading Executor factory method. Default creates a factory that creates DefaultExecutor
+                 *  (i.e. spawn a separate thread for each task) for backward compatibility reasons.
+                 *  Please switch to a better executor such as PooledThreadExecutor.
+                 */
+                std::function<std::shared_ptr<Utils::Threading::Executor>()> executorCreateFn;
+                /**
+                 * Rate Limiter factory for outgoing bandwidth. Default is wide-open.
+                 */
+                std::function<std::shared_ptr<Utils::RateLimits::RateLimiterInterface>()> writeRateLimiterCreateFn;
+                /**
+                 * Rate Limiter factory for incoming bandwidth. Default is wide-open.
+                 */
+                std::function<std::shared_ptr<Utils::RateLimits::RateLimiterInterface>()> readRateLimiterCreateFn;
+                /**
+                 * TelemetryProvider factory. Defaults to Noop provider.
+                 */
+                std::function<std::shared_ptr<smithy::components::tracing::TelemetryProvider>()> telemetryProviderCreateFn;
+
+                static ProviderFactories defaultFactories;
+            };
+
             ClientConfiguration();
 
             /**
@@ -104,6 +139,11 @@ namespace Aws
              */
             virtual ~ClientConfiguration() = default;
 
+            /**
+             * Client configuration factory methods to init client utility classes such as Executor, Retry Strategy
+             */
+            ProviderFactories configFactories = ProviderFactories::defaultFactories;
+
             /**
              * User Agent string user for http calls. This is filled in for you in the constructor. Don't override this unless you have a really good reason.
              */
@@ -165,9 +205,10 @@ namespace Aws
              */
             unsigned long lowSpeedLimit = 1;
             /**
-             * Strategy to use in case of failed requests. Default is DefaultRetryStrategy (i.e. exponential backoff)
+             * Strategy to use in case of failed requests. Default is DefaultRetryStrategy (i.e. exponential backoff).
+             * Provide retry strategy here or via a factory method.
              */
-            std::shared_ptr<RetryStrategy> retryStrategy;
+            std::shared_ptr<RetryStrategy> retryStrategy = nullptr;
             /**
              * Override the http endpoint used to talk to a service.
              */
@@ -227,9 +268,10 @@ namespace Aws
             */
             Aws::Utils::Array<Aws::String> nonProxyHosts;
             /**
-            * Threading Executor implementation. Default uses std::thread::detach()
-            */
-            std::shared_ptr<Aws::Utils::Threading::Executor> executor;
+             * Threading Executor implementation. Default uses std::thread::detach()
+             * Provide executor here or via a factory method.
+             */
+            std::shared_ptr<Aws::Utils::Threading::Executor> executor = nullptr;
             /**
              * If you need to test and want to get around TLS validation errors, do that here.
              * You probably shouldn't use this flag in a production scenario.
@@ -263,12 +305,14 @@ namespace Aws
             Aws::String proxyCaFile;
             /**
              * Rate Limiter implementation for outgoing bandwidth. Default is wide-open.
+             * Provide limiter here or via a factory method.
              */
-            std::shared_ptr<Aws::Utils::RateLimits::RateLimiterInterface> writeRateLimiter;
+            std::shared_ptr<Aws::Utils::RateLimits::RateLimiterInterface> writeRateLimiter = nullptr;
             /**
             * Rate Limiter implementation for incoming bandwidth. Default is wide-open.
+            * Provide limiter here or via a factory method.
             */
-            std::shared_ptr<Aws::Utils::RateLimits::RateLimiterInterface> readRateLimiter;
+            std::shared_ptr<Aws::Utils::RateLimits::RateLimiterInterface> readRateLimiter = nullptr;
             /**
              * Override the http implementation the default factory returns.
              */
@@ -374,10 +418,10 @@ namespace Aws
                                                           const Aws::String& defaultValue);
 
             /**
-             * A wrapper for interfacing with telemetry functionality.
+             * A wrapper for interfacing with telemetry functionality. Defaults to Noop provider.
+             * Provide TelemetryProvider here or via a factory method.
              */
-            std::shared_ptr<smithy::components::tracing::TelemetryProvider> telemetryProvider =
-                smithy::components::tracing::NoopTelemetryProvider::CreateProvider();
+            std::shared_ptr<smithy::components::tracing::TelemetryProvider> telemetryProvider;
         };
 
         /**
diff --git a/src/aws-cpp-sdk-core/include/aws/core/utils/logging/ErrorMacros.h b/src/aws-cpp-sdk-core/include/aws/core/utils/logging/ErrorMacros.h
index 81e0be194d7..dbfd75e82d7 100644
--- a/src/aws-cpp-sdk-core/include/aws/core/utils/logging/ErrorMacros.h
+++ b/src/aws-cpp-sdk-core/include/aws/core/utils/logging/ErrorMacros.h
@@ -66,3 +66,10 @@ if(!m_isInitialized) \
 } \
 Aws::Utils::RAIICounter(this->m_operationsProcessed, &this->m_shutdownSignal)
 
+#define AWS_ASYNC_OPERATION_GUARD(OPERATION) \
+if(!m_isInitialized) \
+{ \
+  AWS_LOGSTREAM_ERROR(#OPERATION, "Unable to call " #OPERATION ": client is not initialized (or already terminated)"); \
+  return handler(this, request, Aws::Client::AWSError<CoreErrors>(CoreErrors::NOT_INITIALIZED, "NOT_INITIALIZED", "Client is not initialized or already terminated", false), handlerContext); \
+} \
+Aws::Utils::RAIICounter(this->m_operationsProcessed, &this->m_shutdownSignal)
diff --git a/src/aws-cpp-sdk-core/source/client/AWSClient.cpp b/src/aws-cpp-sdk-core/source/client/AWSClient.cpp
index 44dfbe770e3..f7b728b134c 100644
--- a/src/aws-cpp-sdk-core/source/client/AWSClient.cpp
+++ b/src/aws-cpp-sdk-core/source/client/AWSClient.cpp
@@ -119,13 +119,19 @@ AWSClient::AWSClient(const Aws::Client::ClientConfiguration& configuration,
     const std::shared_ptr<Aws::Client::AWSAuthSigner>& signer,
     const std::shared_ptr<AWSErrorMarshaller>& errorMarshaller) :
     m_region(configuration.region),
-    m_telemetryProvider(configuration.telemetryProvider),
+    m_telemetryProvider(configuration.telemetryProvider ? configuration.telemetryProvider : configuration.configFactories.telemetryProviderCreateFn()),
     m_signerProvider(Aws::MakeUnique<Aws::Auth::DefaultAuthSignerProvider>(AWS_CLIENT_LOG_TAG, signer)),
-    m_httpClient(CreateHttpClient(configuration)),
+    m_httpClient(CreateHttpClient(
+        [&configuration, this]()
+        {
+            ClientConfiguration tempConfig(configuration);
+            tempConfig.telemetryProvider = m_telemetryProvider;
+            return tempConfig;
+        }())),
     m_errorMarshaller(errorMarshaller),
-    m_retryStrategy(configuration.retryStrategy),
-    m_writeRateLimiter(configuration.writeRateLimiter),
-    m_readRateLimiter(configuration.readRateLimiter),
+    m_retryStrategy(configuration.retryStrategy ? configuration.retryStrategy : configuration.configFactories.retryStrategyCreateFn()),
+    m_writeRateLimiter(configuration.writeRateLimiter ? configuration.writeRateLimiter : configuration.configFactories.writeRateLimiterCreateFn()),
+    m_readRateLimiter(configuration.readRateLimiter ? configuration.readRateLimiter : configuration.configFactories.readRateLimiterCreateFn()),
     m_userAgent(Aws::Client::ComputeUserAgentString(&configuration)),
     m_hash(Aws::Utils::Crypto::CreateMD5Implementation()),
     m_requestTimeoutMs(configuration.requestTimeoutMs),
@@ -138,13 +144,19 @@ AWSClient::AWSClient(const Aws::Client::ClientConfiguration& configuration,
     const std::shared_ptr<Aws::Auth::AWSAuthSignerProvider>& signerProvider,
     const std::shared_ptr<AWSErrorMarshaller>& errorMarshaller) :
     m_region(configuration.region),
-    m_telemetryProvider(configuration.telemetryProvider),
+    m_telemetryProvider(configuration.telemetryProvider ? configuration.telemetryProvider : configuration.configFactories.telemetryProviderCreateFn()),
     m_signerProvider(signerProvider),
-    m_httpClient(CreateHttpClient(configuration)),
+    m_httpClient(CreateHttpClient(
+        [&configuration, this]()
+        {
+            ClientConfiguration tempConfig(configuration);
+            tempConfig.telemetryProvider = m_telemetryProvider;
+            return tempConfig;
+        }())),
     m_errorMarshaller(errorMarshaller),
-    m_retryStrategy(configuration.retryStrategy),
-    m_writeRateLimiter(configuration.writeRateLimiter),
-    m_readRateLimiter(configuration.readRateLimiter),
+    m_retryStrategy(configuration.retryStrategy ? configuration.retryStrategy : configuration.configFactories.retryStrategyCreateFn()),
+    m_writeRateLimiter(configuration.writeRateLimiter ? configuration.writeRateLimiter : configuration.configFactories.writeRateLimiterCreateFn()),
+    m_readRateLimiter(configuration.readRateLimiter ? configuration.readRateLimiter : configuration.configFactories.readRateLimiterCreateFn()),
     m_userAgent(Aws::Client::ComputeUserAgentString(&configuration)),
     m_hash(Aws::Utils::Crypto::CreateMD5Implementation()),
     m_requestTimeoutMs(configuration.requestTimeoutMs),
diff --git a/src/aws-cpp-sdk-core/source/client/ClientConfiguration.cpp b/src/aws-cpp-sdk-core/source/client/ClientConfiguration.cpp
index fcbede8acdc..1b462cab483 100644
--- a/src/aws-cpp-sdk-core/source/client/ClientConfiguration.cpp
+++ b/src/aws-cpp-sdk-core/source/client/ClientConfiguration.cpp
@@ -17,6 +17,7 @@
 #include <aws/core/Version.h>
 #include <aws/core/config/AWSProfileConfigLoader.h>
 #include <aws/core/utils/logging/LogMacros.h>
+#include <smithy/tracing/NoopTelemetryProvider.h>
 
 #include <aws/crt/Config.h>
 
@@ -39,6 +40,19 @@ static const char* AWS_EXECUTION_ENV = "AWS_EXECUTION_ENV";
 static const char* DISABLE_IMDSV1_CONFIG_VAR = "AWS_EC2_METADATA_V1_DISABLED";
 static const char* DISABLE_IMDSV1_ENV_VAR = "ec2_metadata_v1_disabled";
 
+ClientConfiguration::ProviderFactories ClientConfiguration::ProviderFactories::defaultFactories = []()
+{
+    ProviderFactories factories;
+
+    factories.retryStrategyCreateFn = [](){return InitRetryStrategy();};
+    factories.executorCreateFn = [](){return Aws::MakeShared<Aws::Utils::Threading::DefaultExecutor>(CLIENT_CONFIG_TAG);};
+    factories.writeRateLimiterCreateFn = [](){return nullptr;};
+    factories.readRateLimiterCreateFn = [](){return nullptr;};
+    factories.telemetryProviderCreateFn = [](){return smithy::components::tracing::NoopTelemetryProvider::CreateProvider();};
+
+    return factories;
+}();
+
 Aws::String FilterUserAgentToken(char const * const source)
 {
   // Tokens are short textual identifiers that do not include whitespace or delimiters.
@@ -131,7 +145,6 @@ void setLegacyClientConfigurationParameters(ClientConfiguration& clientConfig)
     clientConfig.lowSpeedLimit = 1;
     clientConfig.proxyScheme = Aws::Http::Scheme::HTTP;
     clientConfig.proxyPort = 0;
-    clientConfig.executor = Aws::MakeShared<Aws::Utils::Threading::DefaultExecutor>(CLIENT_CONFIG_TAG);
     clientConfig.verifySSL = true;
     clientConfig.writeRateLimiter = nullptr;
     clientConfig.readRateLimiter = nullptr;
diff --git a/src/aws-cpp-sdk-transfer/include/aws/transfer/TransferManager.h b/src/aws-cpp-sdk-transfer/include/aws/transfer/TransferManager.h
index fee728fd171..e82f152252e 100644
--- a/src/aws-cpp-sdk-transfer/include/aws/transfer/TransferManager.h
+++ b/src/aws-cpp-sdk-transfer/include/aws/transfer/TransferManager.h
@@ -39,10 +39,7 @@ namespace Aws
          */
         struct TransferManagerConfiguration
         {
-            TransferManagerConfiguration(Aws::Utils::Threading::Executor* executor) : s3Client(nullptr), transferExecutor(executor), computeContentMD5(false), transferBufferMaxHeapSize(10 * MB5), bufferSize(MB5)
-            {
-            }
-
+            TransferManagerConfiguration(Aws::Utils::Threading::Executor* executor);
             /**
              * S3 Client to use for transfers. You are responsible for setting this.
              */
@@ -53,6 +50,18 @@ namespace Aws
              * It is not a bug to use the same executor, but at least be aware that this is how the manager will be used.
              */
             Aws::Utils::Threading::Executor* transferExecutor = nullptr;
+
+            /**
+             * Threading Executor shared pointer.
+             * Created and owned by Transfer manager if no raw pointer `transferExecutor` is provided.
+             */
+            std::shared_ptr<Aws::Utils::Threading::Executor> spExecutor = nullptr;
+
+            /**
+             * Threading Executor factory method. Default creates a factory that creates DefaultExecutor
+             */
+            std::function<std::shared_ptr<Utils::Threading::Executor>()> executorCreateFn;
+
             /**
              * When true, TransferManager will calculate the MD5 digest of the content being uploaded.
              * The digest is sent to S3 via an HTTP header enabling the service to perform integrity checks.
diff --git a/src/aws-cpp-sdk-transfer/source/transfer/TransferManager.cpp b/src/aws-cpp-sdk-transfer/source/transfer/TransferManager.cpp
index 30ea0e33aea..9c0c85abe75 100644
--- a/src/aws-cpp-sdk-transfer/source/transfer/TransferManager.cpp
+++ b/src/aws-cpp-sdk-transfer/source/transfer/TransferManager.cpp
@@ -25,6 +25,15 @@ namespace Aws
 {
     namespace Transfer
     {
+        TransferManagerConfiguration::TransferManagerConfiguration(Aws::Utils::Threading::Executor* executor)
+          : s3Client(nullptr),
+            transferExecutor(executor),
+            computeContentMD5(false),
+            transferBufferMaxHeapSize(10 * MB5),
+            bufferSize(MB5)
+        {
+        }
+
         static inline bool IsS3KeyPrefix(const Aws::String& path)
         {
             return (path.find_last_of('/') == path.size() - 1 || path.find_last_of('\\') == path.size() - 1);
@@ -57,6 +66,18 @@ namespace Aws
         TransferManager::TransferManager(const TransferManagerConfiguration& configuration) : m_transferConfig(configuration)
         {
             assert(m_transferConfig.s3Client);
+            if (!m_transferConfig.transferExecutor)
+            {
+                if(!m_transferConfig.spExecutor && m_transferConfig.executorCreateFn)
+                {
+                    m_transferConfig.spExecutor = m_transferConfig.executorCreateFn();
+                }
+                m_transferConfig.transferExecutor = m_transferConfig.spExecutor.get();
+            }
+            if (!m_transferConfig.transferExecutor)
+            {
+                AWS_LOGSTREAM_FATAL(CLASS_TAG, "Failed to init TransferManager: transferExecutor is null");
+            }
             assert(m_transferConfig.transferExecutor);
             m_transferConfig.s3Client->AppendToUserAgent("ft/s3-transfer");
             for (uint64_t i = 0; i < m_transferConfig.transferBufferMaxHeapSize; i += m_transferConfig.bufferSize)
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/ServiceClientSourceInit.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/ServiceClientSourceInit.vm
index c7163e4299f..514c9a02c36 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/ServiceClientSourceInit.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/ServiceClientSourceInit.vm
@@ -1,6 +1,7 @@
 #if(!${onlyGeneratedOperations})
 #set($additionalCtorSignatureArgs = {})
 #set($ctorMemberInitList = [])
+#set($addArgDummy = $ctorMemberInitList.add("m_clientConfiguration(clientConfiguration)"))
 #set($signerCtorArgs = [])
 #set($additionalCtorArgs = {})
 #if($signPayloadsOptional)
@@ -94,7 +95,6 @@ ${className}::${className}(const ${className} &rhs) :
             Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
             Aws::Client::ClientWithAsyncTemplateMethods<${className}>(),
     m_clientConfiguration(rhs.m_clientConfiguration),
-    m_executor(rhs.m_clientConfiguration.executor),
     m_endpointProvider(rhs.m_endpointProvider) {}
 
 ${className}& ${className}::operator=(const ${className} &rhs) {
@@ -110,7 +110,6 @@ ${className}& ${className}::operator=(const ${className} &rhs) {
           rhs.m_clientConfiguration.payloadSigningPolicy,
           /*doubleEncodeValue*/ false);
     m_clientConfiguration = rhs.m_clientConfiguration;
-    m_executor = rhs.m_executor;
     m_endpointProvider = rhs.m_endpointProvider;
     init(m_clientConfiguration);
     return *this;
@@ -128,7 +127,6 @@ S3Client::S3Client(${className} &&rhs) noexcept :
             Aws::MakeShared<S3ErrorMarshaller>(ALLOCATION_TAG)),
             Aws::Client::ClientWithAsyncTemplateMethods<S3Client>(),
     m_clientConfiguration(std::move(rhs.m_clientConfiguration)),
-    m_executor(std::move(rhs.m_clientConfiguration.executor)),
     m_endpointProvider(std::move(rhs.m_endpointProvider)) {}
 
 ${className}& ${className}::operator=(${className} &&rhs) noexcept {
@@ -144,7 +142,6 @@ ${className}& ${className}::operator=(${className} &&rhs) noexcept {
         rhs.m_clientConfiguration.payloadSigningPolicy,
         /*doubleEncodeValue*/ false);
   m_clientConfiguration = std::move(rhs.m_clientConfiguration);
-  m_executor = std::move(rhs.m_executor);
   m_endpointProvider = std::move(rhs.m_endpointProvider);
   init(m_clientConfiguration);
   return *this;
@@ -169,11 +166,6 @@ ${className}& ${className}::operator=(${className} &&rhs) noexcept {
   BASECLASS(clientConfiguration,
             Aws::MakeShared<${signerToMake}>(ALLOCATION_TAG, bearerTokenProvider),
             Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
-#if($serviceModel.endpointRules)
-  m_clientConfiguration(clientConfiguration),
-#end
-  m_executor(clientConfiguration.executor)#if($ctorMemberInitList.isEmpty())
-#else,#end
 #foreach($ctorMemberInit in $ctorMemberInitList)
   ${ctorMemberInit}#if( $foreach.hasNext ),
 
@@ -214,11 +206,6 @@ ${clsWSpace}  ${clsWSpace} ${ctorArgument}#if( $foreach.hasNext ),#else) :#end
 #else#end
 #end),
             Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
-#if($serviceModel.endpointRules)
-  m_clientConfiguration(clientConfiguration),
-#end
-  m_executor(clientConfiguration.executor)#if($ctorMemberInitList.isEmpty())#else,
-#end
 #foreach($ctorMemberInit in $ctorMemberInitList)
   ${ctorMemberInit}#if( $foreach.hasNext ),
 #else#end
@@ -258,11 +245,6 @@ ${clsWSpace}  ${clsWSpace} ${ctorArgument}#if( $foreach.hasNext ),#else) :#end
 #else#end
 #end),
             Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
-#if($serviceModel.endpointRules)
-    m_clientConfiguration(clientConfiguration),
-#end
-    m_executor(clientConfiguration.executor)#if($ctorMemberInitList.isEmpty())#else,
-#end
 #foreach($ctorMemberInit in $ctorMemberInitList)
     ${ctorMemberInit}#if( $foreach.hasNext ),
 #else#end
@@ -302,11 +284,6 @@ ${clsWSpace}  ${clsWSpace} ${ctorArgument}#if( $foreach.hasNext ),#else) :#end
 #else#end
 #end),
             Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
-#if($serviceModel.endpointRules)
-    m_clientConfiguration(clientConfiguration),
-#end
-    m_executor(clientConfiguration.executor)#if($ctorMemberInitList.isEmpty())#else,
-#end
 #foreach($ctorMemberInit in $ctorMemberInitList)
     ${ctorMemberInit}#if( $foreach.hasNext ),
 #else#end
@@ -333,10 +310,7 @@ ${clsWSpace}  ${clsWSpace} ${ctorArgument}#if( $foreach.hasNext ),#else) :#end
   BASECLASS(clientConfiguration,
             signerProvider,
             Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
-#if($serviceModel.endpointRules)
-  m_clientConfiguration(clientConfiguration),
-#end
-  m_executor(clientConfiguration.executor)${virtualAddressingInit}
+${virtualAddressingInit}
 {
   init(m_clientConfiguration);
 }
@@ -362,6 +336,14 @@ std::shared_ptr<${metadata.classNamePrefix}EndpointProviderBase>& ${className}::
 void ${className}::init(const ${clientConfigurationCls}& config)
 {
   AWSClient::SetServiceClientName("${metadata.serviceId}");
+  if (!m_clientConfiguration.executor) {
+    if (!m_clientConfiguration.configFactories.executorCreateFn()) {
+      AWS_LOGSTREAM_FATAL(ALLOCATION_TAG, "Failed to initialize client: config is missing Executor or executorCreateFn");
+      m_isInitialized = false;
+      return;
+    }
+    m_clientConfiguration.executor = m_clientConfiguration.configFactories.executorCreateFn();
+  }
 #if($serviceModel.endpointRules)
   AWS_CHECK_PTR(SERVICE_NAME, m_endpointProvider);
   m_endpointProvider->InitBuiltInParameters(config);
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/ServiceClientSourceLegacyConstructors.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/ServiceClientSourceLegacyConstructors.vm
index e2e1e6c46ec..0dde615a7bf 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/ServiceClientSourceLegacyConstructors.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/ServiceClientSourceLegacyConstructors.vm
@@ -85,10 +85,7 @@
   BASECLASS(clientConfiguration,
             Aws::MakeShared<${signerToMake}>(ALLOCATION_TAG, bearerTokenProvider),
             Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
-#if($serviceModel.endpointRules)
-  m_clientConfiguration(clientConfiguration${signPayloadsClientConfigParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString}),
-#end
-  m_executor(clientConfiguration.executor)#if($ctorMemberInitList.isEmpty())
+  m_clientConfiguration(clientConfiguration${signPayloadsClientConfigParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString})#if($ctorMemberInitList.isEmpty())
 #else,#end
 #foreach($ctorMemberInit in $ctorMemberInitList)
   ${ctorMemberInit}#if( $foreach.hasNext ),
@@ -126,10 +123,7 @@ ${clsWSpace}  ${clsWSpace} ${ctorArgument}#if( $foreach.hasNext ),#else) :#end
 #else#end
 #end),
             Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
-#if($serviceModel.endpointRules)
-  m_clientConfiguration(clientConfiguration${signPayloadsClientConfigParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString}),
-#end
-  m_executor(clientConfiguration.executor)#if($ctorMemberInitList.isEmpty())#else,
+  m_clientConfiguration(clientConfiguration${signPayloadsClientConfigParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString})#if($ctorMemberInitList.isEmpty())#else,
 #end
 #foreach($ctorMemberInit in $ctorMemberInitList)
   ${ctorMemberInit}#if( $foreach.hasNext ),
@@ -167,10 +161,7 @@ ${clsWSpace}  ${clsWSpace} ${ctorArgument}#if( $foreach.hasNext ),#else) :#end
 #else#end
 #end),
             Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
-#if($serviceModel.endpointRules)
-    m_clientConfiguration(clientConfiguration${signPayloadsClientConfigParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString}),
-#end
-    m_executor(clientConfiguration.executor)#if($ctorMemberInitList.isEmpty())#else,
+    m_clientConfiguration(clientConfiguration${signPayloadsClientConfigParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString})#if($ctorMemberInitList.isEmpty())#else,
 #end
 #foreach($ctorMemberInit in $ctorMemberInitList)
     ${ctorMemberInit}#if( $foreach.hasNext ),
@@ -208,10 +199,7 @@ ${clsWSpace}  ${clsWSpace} ${ctorArgument}#if( $foreach.hasNext ),#else) :#end
 #else#end
 #end),
             Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
-#if($serviceModel.endpointRules)
-    m_clientConfiguration(clientConfiguration${signPayloadsClientConfigParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString}),
-#end
-    m_executor(clientConfiguration.executor)#if($ctorMemberInitList.isEmpty())#else,
+    m_clientConfiguration(clientConfiguration${signPayloadsClientConfigParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString})#if($ctorMemberInitList.isEmpty())#else,
 #end
 #foreach($ctorMemberInit in $ctorMemberInitList)
     ${ctorMemberInit}#if( $foreach.hasNext ),
@@ -239,10 +227,7 @@ ${clsWSpace}  ${clsWSpace} ${ctorArgument}#if( $foreach.hasNext ),#else) :#end
   BASECLASS(clientConfiguration,
             signerProvider,
             Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
-#if($serviceModel.endpointRules)
-  m_clientConfiguration(clientConfiguration${signPayloadsClientConfigParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString}),
-#end
-  m_executor(clientConfiguration.executor)
+  m_clientConfiguration(clientConfiguration${signPayloadsClientConfigParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString})
 {
   init(m_clientConfiguration);
 }
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/common/operation/withrequest/OperationAsync.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/common/operation/withrequest/OperationAsync.vm
index f23dfb62014..54e5aed67b2 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/common/operation/withrequest/OperationAsync.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/common/operation/withrequest/OperationAsync.vm
@@ -7,7 +7,7 @@
 #end#if($serviceModel.metadata.serviceId == "S3" && $operation.s3CrtEnabled)
 void ${className}::${operation.name}Async(${constText}${operation.request.shape.name}& request, const ${operation.name}ResponseReceivedHandler& handler, const std::shared_ptr<const Aws::Client::AsyncCallerContext>& context) const
 {
-  m_executor->Submit( [this, ${refText}request, handler, context]()
+  m_clientConfiguration.executor->Submit( [this, ${refText}request, handler, context]()
     {
       handler(this, request, ${operation.name}(request), context);
     } );
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/common/operation/withrequest/OperationOutcomeCallable.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/common/operation/withrequest/OperationOutcomeCallable.vm
index 2a1a71b6adc..ee4ad8d8177 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/common/operation/withrequest/OperationOutcomeCallable.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/common/operation/withrequest/OperationOutcomeCallable.vm
@@ -9,7 +9,7 @@ ${operation.name}OutcomeCallable ${className}::${operation.name}Callable(${const
 {
   auto task = Aws::MakeShared< std::packaged_task< ${operation.name}Outcome() > >(ALLOCATION_TAG, [this, ${refText}request](){ return this->${operation.name}(request); } );
   auto packagedFunction = [task]() { (*task)(); };
-  m_executor->Submit(packagedFunction);
+  m_clientConfiguration.executor->Submit(packagedFunction);
   return task->get_future();
 }
 
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/JsonServiceClientHeader.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/JsonServiceClientHeader.vm
index 522ba82777d..af02be0c2d8 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/JsonServiceClientHeader.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/JsonServiceClientHeader.vm
@@ -75,7 +75,6 @@ namespace ${serviceNamespace}
 #if($serviceModel.endpointRules)
       ${metadata.classNamePrefix}ClientConfiguration m_clientConfiguration;
 #end
-      std::shared_ptr<Aws::Utils::Threading::Executor> m_executor;
 #if($serviceModel.endpointRules)
       std::shared_ptr<${metadata.classNamePrefix}EndpointProviderBase> m_endpointProvider;
 #end
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/JsonServiceEventStreamOperationsSource.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/JsonServiceEventStreamOperationsSource.vm
index a287443d1ad..7a3d274bcc8 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/JsonServiceEventStreamOperationsSource.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/JsonServiceEventStreamOperationsSource.vm
@@ -3,6 +3,7 @@ void ${className}::${operation.name}Async(Model::${operation.request.shape.name}
                 const ${operation.name}ResponseReceivedHandler& handler,
                 const std::shared_ptr<const Aws::Client::AsyncCallerContext>& handlerContext) const
 {
+  AWS_ASYNC_OPERATION_GUARD(${operation.name});
 #parse("com/amazonaws/util/awsclientgenerator/velocity/cpp/common/ServiceClientOperationEndpointPrepareCommonBody.vm")
 #parse("com/amazonaws/util/awsclientgenerator/velocity/cpp/common/ServiceClientOperationRequestRequiredMemberValidate.vm")
 #parse("com/amazonaws/util/awsclientgenerator/velocity/cpp/common/UriRequestQueryParams.vm")
@@ -33,11 +34,7 @@ void ${className}::${operation.name}Async(Model::${operation.request.shape.name}
   auto sem = Aws::MakeShared<Aws::Utils::Threading::Semaphore>(ALLOCATION_TAG, 0, 1);
   request.SetRequestSignedHandler([eventEncoderStream, sem](const Aws::Http::HttpRequest& httpRequest) { eventEncoderStream->SetSignatureSeed(Aws::Client::GetAuthorizationHeader(httpRequest)); sem->ReleaseAll(); });
 
-#if($serviceModel.endpointRules)
-  m_executor->Submit([this, endpointResolutionOutcome, &request, handler, handlerContext] () mutable {
-#else
-  m_executor->Submit([this, uri, &request, handler, handlerContext] () mutable {
-#end
+  m_clientConfiguration.executor->Submit([this, endpointResolutionOutcome, &request, handler, handlerContext] () mutable {
       JsonOutcome outcome = MakeRequest(request, endpointResolutionOutcome.GetResult(), Aws::Http::HttpMethod::HTTP_POST, Aws::Auth::EVENTSTREAM_SIGV4_SIGNER);
       if(outcome.IsSuccess())
       {
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/serviceoperations/withoutrequest/OperationAsync.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/serviceoperations/withoutrequest/OperationAsync.vm
index b633bea6294..a553d351750 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/serviceoperations/withoutrequest/OperationAsync.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/serviceoperations/withoutrequest/OperationAsync.vm
@@ -1,7 +1,7 @@
 #if(0)
 void ${className}::${operation.name}Async(const ${operation.name}ResponseReceivedHandler& handler, const std::shared_ptr<const Aws::Client::AsyncCallerContext>& context) const
 {
-  m_executor->Submit( [this, handler, context]()
+  m_clientConfiguration.executor->Submit( [this, handler, context]()
     {
       handler(this, ${operation.name}(), context);
     } );
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/serviceoperations/withoutrequest/OperationOutcomeCallable.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/serviceoperations/withoutrequest/OperationOutcomeCallable.vm
index ef7ce8e3e44..62d0e6fa45e 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/serviceoperations/withoutrequest/OperationOutcomeCallable.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/serviceoperations/withoutrequest/OperationOutcomeCallable.vm
@@ -3,6 +3,6 @@ ${operation.name}OutcomeCallable ${className}::${operation.name}Callable() const
 {
   auto task = Aws::MakeShared< std::packaged_task< ${operation.name}Outcome() > >(ALLOCATION_TAG, [this](){ return this->${operation.name}(); } );
   auto packagedFunction = [task]() { (*task)(); };
-  m_executor->Submit(packagedFunction);
+  m_clientConfiguration.executor->Submit(packagedFunction);
   return task->get_future();
 }#end
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/rds/RDSClientHeader.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/rds/RDSClientHeader.vm
index fecd46bb06b..45df7a85b72 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/rds/RDSClientHeader.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/rds/RDSClientHeader.vm
@@ -90,7 +90,6 @@ namespace ${rootNamespace}
 #if($serviceModel.endpointRules)
         ${metadata.classNamePrefix}ClientConfiguration m_clientConfiguration;
 #end
-        std::shared_ptr<Aws::Utils::Threading::Executor> m_executor;
 #if($serviceModel.endpointRules)
         std::shared_ptr<${metadata.classNamePrefix}EndpointProviderBase> m_endpointProvider;
 #end
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/S3ClientHeader.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/S3ClientHeader.vm
index 04ddf566724..22d8500e65d 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/S3ClientHeader.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/S3ClientHeader.vm
@@ -265,7 +265,6 @@ namespace ${rootNamespace}
         ${metadata.classNamePrefix}ClientConfiguration m_clientConfiguration;
 #end
 #end
-        std::shared_ptr<Utils::Threading::Executor> m_executor;
 #if($serviceNamespace == "S3Crt")
         struct aws_s3_client* m_s3CrtClient = {};
         struct aws_signing_config_aws m_s3CrtSigningConfig = {};
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/S3CrtServiceClientSourceInit.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/S3CrtServiceClientSourceInit.vm
index b0f1e144cb8..d5871de459a 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/S3CrtServiceClientSourceInit.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/S3CrtServiceClientSourceInit.vm
@@ -44,10 +44,10 @@
 #set($credentialsParam = ", m_credProvider")
 #set($credentialsArg = ", const std::shared_ptr<Aws::Auth::AWSCredentialsProvider> credentialsProvider")
 #set($defaultCredentialsProviderChainParam = "Aws::MakeShared<DefaultAWSCredentialsProviderChain>(ALLOCATION_TAG, credentialsProvider)")
-#set($defaultCredentialsProviderChainMember = ", m_credProvider(Aws::MakeShared<DefaultAWSCredentialsProviderChain>(ALLOCATION_TAG, credentialsProvider))")
+#set($defaultCredentialsProviderChainMember = "m_credProvider(Aws::MakeShared<DefaultAWSCredentialsProviderChain>(ALLOCATION_TAG, credentialsProvider))")
 #set($simpleCredentialsProviderParam = "Aws::MakeShared<SimpleAWSCredentialsProvider>(ALLOCATION_TAG, credentials)")
-#set($simpleCredentialsProviderMember = ", m_credProvider(Aws::MakeShared<SimpleAWSCredentialsProvider>(ALLOCATION_TAG, credentials))")
-#set($credentialsProviderMember = ", m_credProvider(credentialsProvider)")
+#set($simpleCredentialsProviderMember = "m_credProvider(Aws::MakeShared<SimpleAWSCredentialsProvider>(ALLOCATION_TAG, credentials))")
+#set($credentialsProviderMember = "m_credProvider(credentialsProvider)")
 #set($credentialProviderArg = ", const Aws::Auth::DefaultAWSCredentialsProviderChain& credentialsProvider")
 #set($hasEventStreamInputOperation = false)
 #foreach($operation in $serviceModel.operations)
@@ -67,7 +67,6 @@ ${className}::${className}(const ${className} &rhs) :
         Aws::MakeShared<S3CrtErrorMarshaller>(ALLOCATION_TAG)),
     Aws::Client::ClientWithAsyncTemplateMethods<S3CrtClient>(),
     m_clientConfiguration(rhs.m_clientConfiguration),
-    m_executor(rhs.m_clientConfiguration.executor),
     m_endpointProvider(rhs.m_endpointProvider),
     m_identityProvider(rhs.m_identityProvider){}
 
@@ -84,7 +83,6 @@ ${className}& ${className}::operator=(const ${className} &rhs) {
           rhs.m_clientConfiguration.payloadSigningPolicy,
           /*doubleEncodeValue*/ false);
     m_clientConfiguration = rhs.m_clientConfiguration;
-    m_executor = rhs.m_executor;
     m_endpointProvider = rhs.m_endpointProvider;
     init(m_clientConfiguration, m_credProvider);
     return *this;
@@ -102,7 +100,6 @@ ${className}::${className}(${className} &&rhs) noexcept :
             Aws::MakeShared<S3CrtErrorMarshaller>(ALLOCATION_TAG)),
     Aws::Client::ClientWithAsyncTemplateMethods<S3CrtClient>(),
     m_clientConfiguration(std::move(rhs.m_clientConfiguration)),
-    m_executor(std::move(rhs.m_clientConfiguration.executor)),
     m_endpointProvider(std::move(rhs.m_endpointProvider)) {}
 
 ${className}& ${className}::operator=(${className} &&rhs) noexcept {
@@ -118,7 +115,6 @@ ${className}& ${className}::operator=(${className} &&rhs) noexcept {
         rhs.m_clientConfiguration.payloadSigningPolicy,
         /*doubleEncodeValue*/ false);
   m_clientConfiguration = std::move(rhs.m_clientConfiguration);
-  m_executor = std::move(rhs.m_executor);
   m_endpointProvider = std::move(rhs.m_endpointProvider);
   init(m_clientConfiguration, m_credProvider);
   return *this;
@@ -137,9 +133,8 @@ ${className}::${className}(const ${clientConfigurationNamespace}::ClientConfigur
     Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
 #if($serviceModel.endpointRules)
     m_clientConfiguration(clientConfiguration${signPayloadsParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString}),
-    m_executor(clientConfiguration.executor)${defaultCredentialsProviderChainMember},
-#else
-    m_executor(clientConfiguration.executor)${defaultCredentialsProviderChainMember}${virtualAddressingInit}${USEast1RegionalEndpointInitString},
+    ${defaultCredentialsProviderChainMember},
+#else${defaultCredentialsProviderChainMember}${virtualAddressingInit}${USEast1RegionalEndpointInitString},
 #end
     m_identityProvider(Aws::MakeShared<DefaultS3ExpressIdentityProvider>(ALLOCATION_TAG, *this))
 {
@@ -158,9 +153,8 @@ ${className}::${className}(const AWSCredentials& credentials, const ${clientConf
     Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
 #if($serviceModel.endpointRules)
     m_clientConfiguration(clientConfiguration${signPayloadsParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString}),
-    m_executor(clientConfiguration.executor)${simpleCredentialsProviderMember},
-#else
-    m_executor(clientConfiguration.executor)${simpleCredentialsProviderMember}${virtualAddressingInit}${USEast1RegionalEndpointInitString},
+    ${simpleCredentialsProviderMember},
+#else${simpleCredentialsProviderMember}${virtualAddressingInit}${USEast1RegionalEndpointInitString},
 #end
     m_identityProvider(Aws::MakeShared<DefaultS3ExpressIdentityProvider>(ALLOCATION_TAG, *this))
 {
@@ -180,9 +174,9 @@ ${className}::${className}(const std::shared_ptr<AWSCredentialsProvider>& creden
     Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
 #if($serviceModel.endpointRules)
     m_clientConfiguration(clientConfiguration${signPayloadsParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString}),
-    m_executor(clientConfiguration.executor)${credentialsProviderMember},
+    ${credentialsProviderMember},
 #else
-    m_executor(clientConfiguration.executor)${credentialsProviderMember}${virtualAddressingInit}${USEast1RegionalEndpointInitString},
+    ${credentialsProviderMember}${virtualAddressingInit}${USEast1RegionalEndpointInitString},
 #end
     m_identityProvider(Aws::MakeShared<DefaultS3ExpressIdentityProvider>(ALLOCATION_TAG, *this))
 {
@@ -196,9 +190,9 @@ ${className}::${className}(const ${clientConfigurationNamespace}::ClientConfigur
     Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
 #if($serviceModel.endpointRules)
     m_clientConfiguration(clientConfiguration${signPayloadsParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString}),
-    m_executor(clientConfiguration.executor)${defaultCredentialsProviderChainMember},
+    ${defaultCredentialsProviderChainMember},
 #else
-    m_executor(clientConfiguration.executor)${defaultCredentialsProviderChainMember}${virtualAddressingInit}${USEast1RegionalEndpointInitString},
+    ${defaultCredentialsProviderChainMember}${virtualAddressingInit}${USEast1RegionalEndpointInitString},
 #end
     m_identityProvider(Aws::MakeShared<DefaultS3ExpressIdentityProvider>(ALLOCATION_TAG, *this))
 {
@@ -212,9 +206,9 @@ ${className}::${className}(const AWSCredentials& credentials, const ${clientConf
     Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
 #if($serviceModel.endpointRules)
     m_clientConfiguration(clientConfiguration${signPayloadsParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString}),
-    m_executor(clientConfiguration.executor)${simpleCredentialsProviderMember},
+    ${simpleCredentialsProviderMember},
 #else
-    m_executor(clientConfiguration.executor)${simpleCredentialsProviderMember}${virtualAddressingInit}${USEast1RegionalEndpointInitString},
+    ${simpleCredentialsProviderMember}${virtualAddressingInit}${USEast1RegionalEndpointInitString},
 #end
     m_identityProvider(Aws::MakeShared<DefaultS3ExpressIdentityProvider>(ALLOCATION_TAG, *this))
 {
@@ -229,9 +223,9 @@ ${className}::${className}(const std::shared_ptr<AWSCredentialsProvider>& creden
     Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
 #if($serviceModel.endpointRules)
     m_clientConfiguration(clientConfiguration${signPayloadsParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString}),
-    m_executor(clientConfiguration.executor)${virtualAddressingInit},
+    ${virtualAddressingInit},
 #else
-    m_executor(clientConfiguration.executor)${virtualAddressingInit}${USEast1RegionalEndpointInitString}${credentialsProviderMember},
+    ${virtualAddressingInit}${USEast1RegionalEndpointInitString}${credentialsProviderMember},
 #end
     m_identityProvider(Aws::MakeShared<DefaultS3ExpressIdentityProvider>(ALLOCATION_TAG, *this))
 {
@@ -246,9 +240,9 @@ ${className}::${className}(const std::shared_ptr<Aws::Auth::AWSAuthSignerProvide
     Aws::MakeShared<${metadata.classNamePrefix}ErrorMarshaller>(ALLOCATION_TAG)),
 #if($serviceModel.endpointRules)
     m_clientConfiguration(clientConfiguration${signPayloadsParam}${virtualAddressingInit}${USEast1RegionalEndpointInitString}),
-    m_executor(clientConfiguration.executor)${virtualAddressingInit},
+    ${virtualAddressingInit},
 #else
-    m_executor(clientConfiguration.executor)${virtualAddressingInit},
+    ${virtualAddressingInit},
 #end
     m_identityProvider(Aws::MakeShared<DefaultS3ExpressIdentityProvider>(ALLOCATION_TAG, *this))
 {
@@ -279,6 +273,14 @@ void ${className}::init(const ${clientConfigurationNamespace}::ClientConfigurati
     const std::shared_ptr<Aws::Auth::AWSCredentialsProvider> credentialsProvider)
 {
   AWSClient::SetServiceClientName("${metadata.serviceId}");
+  if (!m_clientConfiguration.executor) {
+    if (!m_clientConfiguration.configFactories.executorCreateFn()) {
+      AWS_LOGSTREAM_FATAL(ALLOCATION_TAG, "Failed to initialize client: config is missing Executor or executorCreateFn");
+      m_isInitialized = false;
+      return;
+    }
+    m_clientConfiguration.executor = m_clientConfiguration.configFactories.executorCreateFn();
+  }
 #if($serviceModel.endpointRules)
   m_endpointProvider = Aws::MakeShared<S3CrtEndpointProvider>(ALLOCATION_TAG);
   AWS_CHECK_PTR(SERVICE_NAME, m_endpointProvider);
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/S3CrtSpecificOperations.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/S3CrtSpecificOperations.vm
index a0e931e9c77..abcc93d2373 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/S3CrtSpecificOperations.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3/s3-crt/S3CrtSpecificOperations.vm
@@ -259,6 +259,7 @@ static void ${operation.name}RequestShutdownCallback(void *user_data)
 #if($operation.request)
 void ${className}::${operation.name}Async(${constText}${operation.request.shape.name}& request, const ${operation.name}ResponseReceivedHandler& handler, const std::shared_ptr<const Aws::Client::AsyncCallerContext>& handlerContext) const
 {
+  AWS_ASYNC_OPERATION_GUARD(${operation.name});
 #parse("com/amazonaws/util/awsclientgenerator/velocity/cpp/common/ServiceClientOperationRequestRequiredMemberValidate.vm")
 #parse("com/amazonaws/util/awsclientgenerator/velocity/cpp/common/ServiceClientOperationEndpointPrepareCommonBody.vm")
 #parse("com/amazonaws/util/awsclientgenerator/velocity/cpp/common/UriRequestQueryParams.vm")
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3control/S3ControlClientHeader.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3control/S3ControlClientHeader.vm
index 56a90312092..e5197ddb40e 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3control/S3ControlClientHeader.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/s3control/S3ControlClientHeader.vm
@@ -96,7 +96,6 @@ namespace ${metadata.namespace}
 #if($serviceModel.endpointRules)
         ${metadata.classNamePrefix}ClientConfiguration m_clientConfiguration;
 #end
-        std::shared_ptr<Utils::Threading::Executor> m_executor;
 #if(!$serviceModel.endpointRules)
         bool m_useDualStack = false;
         bool m_useArnRegion = false;
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/XmlServiceClientHeader.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/XmlServiceClientHeader.vm
index abdc4804b6c..f62170e763d 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/XmlServiceClientHeader.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/XmlServiceClientHeader.vm
@@ -85,7 +85,6 @@ namespace ${serviceNamespace}
 #if($serviceModel.endpointRules)
         ${metadata.classNamePrefix}ClientConfiguration m_clientConfiguration;
 #end
-        std::shared_ptr<Aws::Utils::Threading::Executor> m_executor;
 #if($serviceModel.endpointRules)
         std::shared_ptr<${metadata.classNamePrefix}EndpointProviderBase> m_endpointProvider;
 #end
diff --git a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/rest/RestXmlServiceClientOperations.vm b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/rest/RestXmlServiceClientOperations.vm
index 55491bc0cb8..710012b7bf6 100644
--- a/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/rest/RestXmlServiceClientOperations.vm
+++ b/tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/xml/rest/RestXmlServiceClientOperations.vm
@@ -150,13 +150,13 @@ ${operation.name}OutcomeCallable ${className}::${operation.name}Callable() const
 {
   auto task = Aws::MakeShared< std::packaged_task< ${operation.name}Outcome() > >(ALLOCATION_TAG, [this](){ return this->${operation.name}(); } );
   auto packagedFunction = [task]() { (*task)(); };
-  m_executor->Submit(packagedFunction);
+  m_clientConfiguration.executor->Submit(packagedFunction);
   return task->get_future();
 }
 
 void ${className}::${operation.name}Async(${constText}${operation.name}ResponseReceivedHandler& handler, const std::shared_ptr<const Aws::Client::AsyncCallerContext>& context) const
 {
-  m_executor->Submit( [this, handler, context]()
+  m_clientConfiguration.executor->Submit( [this, handler, context]()
     {
       handler(this, ${operation.name}(), context);
     } );