diff --git a/Adaptors/Amqp/src/ConnectionAmqp.cs b/Adaptors/Amqp/src/ConnectionAmqp.cs
index dfdc18031..208d60464 100644
--- a/Adaptors/Amqp/src/ConnectionAmqp.cs
+++ b/Adaptors/Amqp/src/ConnectionAmqp.cs
@@ -133,7 +133,7 @@ await Task.Delay(1000 * retry,
   private static void OnCloseConnection(Error?  error,
                                         ILogger logger)
   {
-    if (error == null)
+    if (error is null)
     {
       logger.LogInformation("AMQP Connection closed with no error");
     }
diff --git a/Adaptors/MongoDB/src/AuthenticationTable.cs b/Adaptors/MongoDB/src/AuthenticationTable.cs
index e81b53f2c..07b61b215 100644
--- a/Adaptors/MongoDB/src/AuthenticationTable.cs
+++ b/Adaptors/MongoDB/src/AuthenticationTable.cs
@@ -183,11 +183,11 @@ await sessionProvider_.Init(cancellationToken)
     var                              sessionHandle  = sessionProvider_.Get();
     Expression<Func<UserData, bool>> expression;
     // Id matching has priority
-    if (id != null)
+    if (id is not null)
     {
       expression = data => data.UserId == id;
     }
-    else if (username != null)
+    else if (username is not null)
     {
       expression = data => data.Username == username;
     }
@@ -280,7 +280,7 @@ await sessionProvider_.Init(cancellationToken)
   /// <returns>The user to identity pipeline</returns>
   private PipelineDefinition<UserData, MongoAuthResult> GetUserToIdentityPipeline()
   {
-    if (userToIdentityPipeline_ != null)
+    if (userToIdentityPipeline_ is not null)
     {
       return userToIdentityPipeline_;
     }
@@ -396,7 +396,7 @@ private PipelineDefinition<UserData, MongoAuthResult> GetUserToIdentityPipeline(
   /// <returns>Pipeline to obtain the identity from the certificate</returns>
   private PipelineDefinition<AuthData, MongoAuthResult> GetAuthToIdentityPipeline()
   {
-    if (authToIdentityPipeline_ != null)
+    if (authToIdentityPipeline_ is not null)
     {
       return authToIdentityPipeline_;
     }
diff --git a/Common/src/Auth/Authentication/Authenticator.cs b/Common/src/Auth/Authentication/Authenticator.cs
index 305d0543a..4e56c5878 100644
--- a/Common/src/Auth/Authentication/Authenticator.cs
+++ b/Common/src/Auth/Authentication/Authenticator.cs
@@ -225,7 +225,7 @@ protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
                    .ConfigureAwait(false);
 
 
-      if (identity == null)
+      if (identity is null)
       {
         return AuthenticateResult.Fail("Unrecognized user certificate");
       }
@@ -236,7 +236,7 @@ protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
     }
 
     // Try to impersonate only if at least one of the impersonation headers is set
-    if (impersonationId != null || impersonationUsername != null)
+    if (impersonationId is not null || impersonationUsername is not null)
     {
       // Only users with the impersonate permission can impersonate
       if (identity.HasClaim(c => c.Type == GeneralService.Impersonate.Claim.Type))
@@ -296,7 +296,7 @@ protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
                                                                   cancellationToken)
                                  .ConfigureAwait(false);
 
-    if (result == null)
+    if (result is null)
     {
       return null;
     }
@@ -324,7 +324,7 @@ public async Task<ClaimsPrincipal> GetImpersonatedIdentityAsync(ClaimsPrincipal
                                                                   CancellationToken cancellationToken = default)
   {
     UserAuthenticationResult? result;
-    if (impersonationId != null || impersonationUsername != null)
+    if (impersonationId is not null || impersonationUsername is not null)
     {
       result = await authTable_.GetIdentityFromUserAsync(impersonationId,
                                                          impersonationUsername,
@@ -336,7 +336,7 @@ public async Task<ClaimsPrincipal> GetImpersonatedIdentityAsync(ClaimsPrincipal
       throw new AuthenticationException("Impersonation headers are missing");
     }
 
-    if (result == null)
+    if (result is null)
     {
       throw new AuthenticationException("User being impersonated does not exist");
     }
diff --git a/Common/src/Injection/AdapterLoadContext.cs b/Common/src/Injection/AdapterLoadContext.cs
index 2c52bb302..b88ad9981 100644
--- a/Common/src/Injection/AdapterLoadContext.cs
+++ b/Common/src/Injection/AdapterLoadContext.cs
@@ -39,7 +39,7 @@ public AdapterLoadContext(string assemblyPath)
   protected override Assembly? Load(AssemblyName assemblyName)
   {
     var assemblyPath = resolver_.ResolveAssemblyToPath(assemblyName);
-    return assemblyPath != null
+    return assemblyPath is not null
              ? LoadFromAssemblyPath(assemblyPath)
              : null;
   }
@@ -48,7 +48,7 @@ public AdapterLoadContext(string assemblyPath)
   protected override IntPtr LoadUnmanagedDll(string unmanagedDllName)
   {
     var libraryPath = resolver_.ResolveUnmanagedDllToPath(unmanagedDllName);
-    return libraryPath != null
+    return libraryPath is not null
              ? LoadUnmanagedDllFromPath(libraryPath)
              : IntPtr.Zero;
   }
diff --git a/Common/src/Injection/ServiceCollectionExt.cs b/Common/src/Injection/ServiceCollectionExt.cs
index 1f7ed19d3..ee56fc356 100644
--- a/Common/src/Injection/ServiceCollectionExt.cs
+++ b/Common/src/Injection/ServiceCollectionExt.cs
@@ -63,7 +63,7 @@ public static IServiceCollection AddArmoniKWorkerConnection(this IServiceCollect
 
     var computePlanOptions = computePlanComponent.Get<ComputePlane>();
 
-    if (computePlanOptions == null)
+    if (computePlanOptions is null)
     {
       return services;
     }
diff --git a/Common/src/Pollster/AgentHandler.cs b/Common/src/Pollster/AgentHandler.cs
index 36c22aeaf..bcef12d56 100644
--- a/Common/src/Pollster/AgentHandler.cs
+++ b/Common/src/Pollster/AgentHandler.cs
@@ -84,7 +84,7 @@ public AgentHandler(LoggerInit            loggerInit,
 
     try
     {
-      if (computePlaneOptions.AgentChannel?.Address == null)
+      if (computePlaneOptions.AgentChannel?.Address is null)
       {
         throw new ArgumentNullException(nameof(computePlaneOptions),
                                         $"{nameof(computePlaneOptions.AgentChannel)} is null");
diff --git a/Common/src/Pollster/TaskHandler.cs b/Common/src/Pollster/TaskHandler.cs
index 80a10674e..cd4b96bfb 100644
--- a/Common/src/Pollster/TaskHandler.cs
+++ b/Common/src/Pollster/TaskHandler.cs
@@ -521,7 +521,7 @@ await taskTable_.ReleaseTask(taskData_,
   ///   The metadata of the task
   /// </returns>
   public TaskInfo GetAcquiredTaskInfo()
-    => taskData_ != null
+    => taskData_ is not null
          ? new TaskInfo(taskData_.SessionId,
                         taskData_.TaskId,
                         messageHandler_.MessageId)
@@ -537,7 +537,7 @@ public TaskInfo GetAcquiredTaskInfo()
   /// <exception cref="ObjectDataNotFoundException">input data are not found</exception>
   public async Task PreProcessing()
   {
-    if (taskData_ == null)
+    if (taskData_ is null)
     {
       throw new NullReferenceException();
     }
@@ -574,7 +574,7 @@ await HandleErrorRequeueAsync(e,
   /// <exception cref="ArmoniKException">worker pipe is not initialized</exception>
   public async Task ExecuteTask()
   {
-    if (taskData_ == null || sessionData_ == null)
+    if (taskData_ is null || sessionData_ is null)
     {
       throw new NullReferenceException();
     }
diff --git a/Common/src/Storage/TaskLifeCycleHelper.cs b/Common/src/Storage/TaskLifeCycleHelper.cs
index 24e1efc59..b36ef976a 100644
--- a/Common/src/Storage/TaskLifeCycleHelper.cs
+++ b/Common/src/Storage/TaskLifeCycleHelper.cs
@@ -55,7 +55,7 @@ public static TaskOptions ValidateSession(SessionData       sessionData,
                                             ILogger           logger,
                                             CancellationToken cancellationToken)
   {
-    var localOptions = submissionOptions != null
+    var localOptions = submissionOptions is not null
                          ? TaskOptions.Merge(submissionOptions,
                                              sessionData.Options)
                          : sessionData.Options;
diff --git a/Common/src/Stream/Worker/WorkerStreamHandler.cs b/Common/src/Stream/Worker/WorkerStreamHandler.cs
index 6f0d38f9e..8b3bf7e39 100644
--- a/Common/src/Stream/Worker/WorkerStreamHandler.cs
+++ b/Common/src/Stream/Worker/WorkerStreamHandler.cs
@@ -138,7 +138,7 @@ public async Task<Output> StartTaskProcessing(TaskData          taskData,
                                                 string            dataFolder,
                                                 CancellationToken cancellationToken)
   {
-    if (workerClient_ == null)
+    if (workerClient_ is null)
     {
       throw new ArmoniKException("Worker client should be initialized");
     }
diff --git a/Common/src/gRPC/Convertors/TaskTableExt.cs b/Common/src/gRPC/Convertors/TaskTableExt.cs
index fed30f1f8..8e020efd9 100644
--- a/Common/src/gRPC/Convertors/TaskTableExt.cs
+++ b/Common/src/gRPC/Convertors/TaskTableExt.cs
@@ -77,10 +77,10 @@ public static async Task<long> UpdateAllTaskStatusAsync(this ITaskTable   taskTa
                                                           TaskStatus        status,
                                                           CancellationToken cancellationToken = default)
   {
-    if (filter.Included != null && (filter.Included.Statuses.Contains(TaskStatus.Completed.ToGrpcStatus()) ||
-                                    filter.Included.Statuses.Contains(TaskStatus.Cancelled.ToGrpcStatus()) ||
-                                    filter.Included.Statuses.Contains(TaskStatus.Error.ToGrpcStatus())     ||
-                                    filter.Included.Statuses.Contains(TaskStatus.Retried.ToGrpcStatus())))
+    if (filter.Included is not null && (filter.Included.Statuses.Contains(TaskStatus.Completed.ToGrpcStatus()) ||
+                                        filter.Included.Statuses.Contains(TaskStatus.Cancelled.ToGrpcStatus()) ||
+                                        filter.Included.Statuses.Contains(TaskStatus.Error.ToGrpcStatus())     ||
+                                        filter.Included.Statuses.Contains(TaskStatus.Retried.ToGrpcStatus())))
     {
       throw new ArmoniKException("The given TaskFilter contains a terminal state, update forbidden");
     }
diff --git a/Common/src/gRPC/ListApplicationsRequestExt.cs b/Common/src/gRPC/ListApplicationsRequestExt.cs
index 61e79651e..375456c4a 100644
--- a/Common/src/gRPC/ListApplicationsRequestExt.cs
+++ b/Common/src/gRPC/ListApplicationsRequestExt.cs
@@ -75,7 +75,7 @@ public static Expression<Func<TaskData, bool>> ToApplicationFilter(this Filters
     Expression<Func<TaskData, bool>> expr = data => false;
 
 
-    if (filters.Or == null || !filters.Or.Any())
+    if (filters.Or is null || !filters.Or.Any())
     {
       return data => true;
     }
diff --git a/Common/src/gRPC/ListPartitionsRequestExt.cs b/Common/src/gRPC/ListPartitionsRequestExt.cs
index a4ba6a798..28a40d806 100644
--- a/Common/src/gRPC/ListPartitionsRequestExt.cs
+++ b/Common/src/gRPC/ListPartitionsRequestExt.cs
@@ -61,7 +61,7 @@ public static Expression<Func<PartitionData, bool>> ToPartitionFilter(this Filte
   {
     Expression<Func<PartitionData, bool>> expr = data => false;
 
-    if (filters.Or == null || !filters.Or.Any())
+    if (filters.Or is null || !filters.Or.Any())
     {
       return data => true;
     }
diff --git a/Common/src/gRPC/ListResultsRequestExt.cs b/Common/src/gRPC/ListResultsRequestExt.cs
index 9ce83f160..c6ea8ff6a 100644
--- a/Common/src/gRPC/ListResultsRequestExt.cs
+++ b/Common/src/gRPC/ListResultsRequestExt.cs
@@ -66,7 +66,7 @@ public static Expression<Func<Result, bool>> ToResultFilter(this Filters filters
   {
     Expression<Func<Result, bool>> expr = data => false;
 
-    if (filters.Or == null || !filters.Or.Any())
+    if (filters.Or is null || !filters.Or.Any())
     {
       return data => true;
     }
diff --git a/Common/src/gRPC/ListSessionsRequestExt.cs b/Common/src/gRPC/ListSessionsRequestExt.cs
index 6b4fc86af..020e55e15 100644
--- a/Common/src/gRPC/ListSessionsRequestExt.cs
+++ b/Common/src/gRPC/ListSessionsRequestExt.cs
@@ -69,7 +69,7 @@ public static Expression<Func<SessionData, bool>> ToSessionDataFilter(this Filte
   {
     Expression<Func<SessionData, bool>> expr = data => false;
 
-    if (filters.Or == null || !filters.Or.Any())
+    if (filters.Or is null || !filters.Or.Any())
     {
       return data => true;
     }
diff --git a/Common/src/gRPC/ListTasksRequestExt.cs b/Common/src/gRPC/ListTasksRequestExt.cs
index 2911a2421..1a979f64b 100644
--- a/Common/src/gRPC/ListTasksRequestExt.cs
+++ b/Common/src/gRPC/ListTasksRequestExt.cs
@@ -65,7 +65,7 @@ public static Expression<Func<TaskData, bool>> ToTaskDataFilter(this Filters fil
   {
     Expression<Func<TaskData, bool>> expr = data => false;
 
-    if (filters.Or == null || !filters.Or.Any())
+    if (filters.Or is null || !filters.Or.Any())
     {
       return data => true;
     }
diff --git a/Common/src/gRPC/Services/GrpcAgentService.cs b/Common/src/gRPC/Services/GrpcAgentService.cs
index 1cbeaca4d..113439e7d 100644
--- a/Common/src/gRPC/Services/GrpcAgentService.cs
+++ b/Common/src/gRPC/Services/GrpcAgentService.cs
@@ -60,7 +60,7 @@ public Task Stop()
   public override async Task<CreateTaskReply> CreateTask(IAsyncStreamReader<CreateTaskRequest> requestStream,
                                                          ServerCallContext                     context)
   {
-    if (agent_ == null)
+    if (agent_ is null)
     {
       return new CreateTaskReply
              {
@@ -247,7 +247,7 @@ await agent_.NotifyResultData(agent_.Token,
   public override async Task<DataResponse> GetCommonData(DataRequest       request,
                                                          ServerCallContext context)
   {
-    if (agent_ != null)
+    if (agent_ is not null)
     {
       return new DataResponse
              {
@@ -266,7 +266,7 @@ public override async Task<DataResponse> GetCommonData(DataRequest       request
   public override async Task<DataResponse> GetResourceData(DataRequest       request,
                                                            ServerCallContext context)
   {
-    if (agent_ != null)
+    if (agent_ is not null)
     {
       return new DataResponse
              {
@@ -285,7 +285,7 @@ public override async Task<DataResponse> GetResourceData(DataRequest       reque
   public override async Task<DataResponse> GetDirectData(DataRequest       request,
                                                          ServerCallContext context)
   {
-    if (agent_ != null)
+    if (agent_ is not null)
     {
       return new DataResponse
              {
@@ -304,7 +304,7 @@ public override async Task<DataResponse> GetDirectData(DataRequest       request
   public override async Task<NotifyResultDataResponse> NotifyResultData(NotifyResultDataRequest request,
                                                                         ServerCallContext       context)
   {
-    if (agent_ != null)
+    if (agent_ is not null)
     {
       var results = await agent_.NotifyResultData(request.CommunicationToken,
                                                   request.Ids.ViewSelect(identifier => identifier.ResultId),
@@ -328,7 +328,7 @@ public override async Task<NotifyResultDataResponse> NotifyResultData(NotifyResu
   public override async Task<CreateResultsMetaDataResponse> CreateResultsMetaData(CreateResultsMetaDataRequest request,
                                                                                   ServerCallContext            context)
   {
-    if (agent_ != null)
+    if (agent_ is not null)
     {
       var results = await agent_.CreateResultsMetaData(request.CommunicationToken,
                                                        request.Results.ViewSelect(create => new ResultCreationRequest(request.SessionId,
@@ -360,7 +360,7 @@ public override async Task<CreateResultsMetaDataResponse> CreateResultsMetaData(
   public override async Task<SubmitTasksResponse> SubmitTasks(SubmitTasksRequest request,
                                                               ServerCallContext  context)
   {
-    if (agent_ != null)
+    if (agent_ is not null)
     {
       var createdTasks = await agent_.SubmitTasks(request.TaskCreations.ViewSelect(creation => new TaskSubmissionRequest(creation.PayloadId,
                                                                                                                          creation.TaskOptions.ToNullableTaskOptions(),
@@ -402,7 +402,7 @@ public override async Task<SubmitTasksResponse> SubmitTasks(SubmitTasksRequest r
   public override async Task<CreateResultsResponse> CreateResults(CreateResultsRequest request,
                                                                   ServerCallContext    context)
   {
-    if (agent_ != null)
+    if (agent_ is not null)
     {
       var results = await agent_.CreateResults(request.CommunicationToken,
                                                request.Results.ViewSelect(create => (new ResultCreationRequest(request.SessionId,
diff --git a/Common/src/gRPC/Validators/EventSubscriptionRequestValidator.cs b/Common/src/gRPC/Validators/EventSubscriptionRequestValidator.cs
index 038c8ab11..2f90463d7 100644
--- a/Common/src/gRPC/Validators/EventSubscriptionRequestValidator.cs
+++ b/Common/src/gRPC/Validators/EventSubscriptionRequestValidator.cs
@@ -32,7 +32,7 @@ public class EventSubscriptionRequestValidator : AbstractValidator<EventSubscrip
   /// <inheritdoc />
   public override ValidationResult Validate(ValidationContext<EventSubscriptionRequest> context)
   {
-    if (context.InstanceToValidate.ResultsFilters != null)
+    if (context.InstanceToValidate.ResultsFilters is not null)
     {
       foreach (var filtersAnd in context.InstanceToValidate.ResultsFilters.Or)
       {
@@ -74,7 +74,7 @@ public override ValidationResult Validate(ValidationContext<EventSubscriptionReq
     }
 
     // ReSharper disable once InvertIf
-    if (context.InstanceToValidate.TasksFilters != null)
+    if (context.InstanceToValidate.TasksFilters is not null)
     {
       foreach (var filtersAnd in context.InstanceToValidate.TasksFilters.Or)
       {
diff --git a/Common/tests/Auth/AuthenticationCacheTest.cs b/Common/tests/Auth/AuthenticationCacheTest.cs
index f1253c46b..ff2648a48 100644
--- a/Common/tests/Auth/AuthenticationCacheTest.cs
+++ b/Common/tests/Auth/AuthenticationCacheTest.cs
@@ -98,7 +98,7 @@ public void CacheShouldMiss(string  connectionId,
                                                         fingerprint,
                                                         impersonationId,
                                                         impersonationUsername));
-    Assert.IsTrue(result == null || BaseIdentity != result);
+    Assert.IsTrue(result is null || BaseIdentity != result);
   }
 
   [Test]
diff --git a/Common/tests/Auth/AuthenticationIntegrationTest.cs b/Common/tests/Auth/AuthenticationIntegrationTest.cs
index bf9983f0a..6ee71164c 100644
--- a/Common/tests/Auth/AuthenticationIntegrationTest.cs
+++ b/Common/tests/Auth/AuthenticationIntegrationTest.cs
@@ -100,7 +100,7 @@ public void BeforeAll()
   [OneTimeTearDown]
   public async Task TearDown()
   {
-    if (helper_ != null)
+    if (helper_ is not null)
     {
       await helper_.StopServer()
                    .ConfigureAwait(false);
diff --git a/Common/tests/Auth/CheckAuthenticationAttributes.cs b/Common/tests/Auth/CheckAuthenticationAttributes.cs
index a2d619fe0..f48c974d0 100644
--- a/Common/tests/Auth/CheckAuthenticationAttributes.cs
+++ b/Common/tests/Auth/CheckAuthenticationAttributes.cs
@@ -49,7 +49,7 @@ public static List<TestCaseData> GetAllServices()
                                   .Where(t => t.BaseType?.Namespace?.ToUpperInvariant()
                                                .StartsWith("ArmoniK.Api.gRPC".ToUpperInvariant()) == true)
                                   // Keep only the non-nested types
-                                  .Where(t => t.DeclaringType == null)
+                                  .Where(t => t.DeclaringType is null)
                                   .Select(t => new TestCaseData(t).SetName("{m}" + $"({t.Name})")));
 
   /// <summary>
diff --git a/Common/tests/Auth/MockAuthenticationTable.cs b/Common/tests/Auth/MockAuthenticationTable.cs
index b78db433d..643202abe 100644
--- a/Common/tests/Auth/MockAuthenticationTable.cs
+++ b/Common/tests/Auth/MockAuthenticationTable.cs
@@ -49,7 +49,7 @@ public Task Init(CancellationToken cancellationToken)
   public Task<UserAuthenticationResult?> GetIdentityFromUserAsync(string?           id,
                                                                   string?           username,
                                                                   CancellationToken cancellationToken)
-    => Task.FromResult(identities_.Find(i => id             != null
+    => Task.FromResult(identities_.Find(i => id is not null
                                                ? i.UserId   == id
                                                : i.UserName == username)
                                   ?.ToUserAuthenticationResult());
diff --git a/Common/tests/HealthChecks/HowHealthCheckWorkTest.cs b/Common/tests/HealthChecks/HowHealthCheckWorkTest.cs
index c382675a9..e3e238387 100644
--- a/Common/tests/HealthChecks/HowHealthCheckWorkTest.cs
+++ b/Common/tests/HealthChecks/HowHealthCheckWorkTest.cs
@@ -104,7 +104,7 @@ public virtual async Task TearDown()
     server_?.Dispose();
     server_ = null;
 
-    if (app_ != null)
+    if (app_ is not null)
     {
       await app_.DisposeAsync()
                 .ConfigureAwait(false);
diff --git a/Common/tests/Helpers/GrpcSubmitterServiceHelper.cs b/Common/tests/Helpers/GrpcSubmitterServiceHelper.cs
index 70e09604f..737f0cfea 100644
--- a/Common/tests/Helpers/GrpcSubmitterServiceHelper.cs
+++ b/Common/tests/Helpers/GrpcSubmitterServiceHelper.cs
@@ -144,7 +144,7 @@ public async Task<ChannelBase> CreateChannel()
   {
     using (channelMutex_)
     {
-      if (handler_ == null)
+      if (handler_ is null)
       {
         await StartServer()
           .ConfigureAwait(false);
diff --git a/Common/tests/Helpers/TestServerCallContext.cs b/Common/tests/Helpers/TestServerCallContext.cs
index 3b5517f5c..684799155 100644
--- a/Common/tests/Helpers/TestServerCallContext.cs
+++ b/Common/tests/Helpers/TestServerCallContext.cs
@@ -72,7 +72,7 @@ protected override ContextPropagationToken CreatePropagationTokenCore(ContextPro
 
   protected override Task WriteResponseHeadersAsyncCore(Metadata? responseHeaders)
   {
-    if (ResponseHeaders != null)
+    if (ResponseHeaders is not null)
     {
       throw new InvalidOperationException("Response headers have already been written.");
     }
diff --git a/Common/tests/Pollster/TaskHandlerTest.cs b/Common/tests/Pollster/TaskHandlerTest.cs
index 2862b70f1..854272fda 100644
--- a/Common/tests/Pollster/TaskHandlerTest.cs
+++ b/Common/tests/Pollster/TaskHandlerTest.cs
@@ -1335,7 +1335,7 @@ await testServiceProvider.TaskHandler.PreProcessing()
     await testServiceProvider.TaskHandler.ExecuteTask()
                              .ConfigureAwait(false);
 
-    if (agentHandler.Agent == null)
+    if (agentHandler.Agent is null)
     {
       throw new NullReferenceException(nameof(agentHandler.Agent));
     }
diff --git a/Common/tests/Submitter/ExceptionInterceptorTests.cs b/Common/tests/Submitter/ExceptionInterceptorTests.cs
index eb6f9d987..2fdb62720 100644
--- a/Common/tests/Submitter/ExceptionInterceptorTests.cs
+++ b/Common/tests/Submitter/ExceptionInterceptorTests.cs
@@ -69,7 +69,7 @@ public void OneTimeSetUp()
   [TearDown]
   public async Task TearDown()
   {
-    if (helper_ != null)
+    if (helper_ is not null)
     {
       await helper_.StopServer()
                    .ConfigureAwait(false);
diff --git a/Common/tests/Submitter/IntegrationGrpcSubmitterServiceTest.cs b/Common/tests/Submitter/IntegrationGrpcSubmitterServiceTest.cs
index 7538e5174..d0d789a06 100644
--- a/Common/tests/Submitter/IntegrationGrpcSubmitterServiceTest.cs
+++ b/Common/tests/Submitter/IntegrationGrpcSubmitterServiceTest.cs
@@ -73,7 +73,7 @@ public void OneTimeSetUp()
   [TearDown]
   public async Task TearDown()
   {
-    if (helper_ != null)
+    if (helper_ is not null)
     {
       await helper_.StopServer()
                    .ConfigureAwait(false);
diff --git a/Control/PartitionMetrics/src/ArmoniKMeter.cs b/Control/PartitionMetrics/src/ArmoniKMeter.cs
index 11b7ac673..730549edd 100644
--- a/Control/PartitionMetrics/src/ArmoniKMeter.cs
+++ b/Control/PartitionMetrics/src/ArmoniKMeter.cs
@@ -128,7 +128,7 @@ private async Task<IDictionary<string, long>> FetchMeasurementsAsync(Cancellatio
     {
       var metricValue = (metrics[$"armonik_{partition.PartitionId}_tasks_queued"] as Metric)?.MetricValue;
 
-      if (metricValue != null)
+      if (metricValue is not null)
       {
         var numberOfTasks = (long)metricValue.Value;
         measurements[partition.PartitionId] = Math.Min(numberOfTasks,
diff --git a/Tests/Stream/Common/TestPayload.cs b/Tests/Stream/Common/TestPayload.cs
index 26d1c4877..e23165da9 100644
--- a/Tests/Stream/Common/TestPayload.cs
+++ b/Tests/Stream/Common/TestPayload.cs
@@ -51,7 +51,7 @@ public byte[] Serialize()
 
   public static TestPayload? Deserialize(byte[]? payload)
   {
-    if (payload == null || payload.Length == 0)
+    if (payload is null || payload.Length == 0)
     {
       return new TestPayload
              {
diff --git a/Tests/Stream/Server/WorkerService.cs b/Tests/Stream/Server/WorkerService.cs
index 84edca9c7..8bb8f9c51 100644
--- a/Tests/Stream/Server/WorkerService.cs
+++ b/Tests/Stream/Server/WorkerService.cs
@@ -69,7 +69,7 @@ public override async Task<Output> Process(ITaskHandler taskHandler)
     try
     {
       var payload = TestPayload.Deserialize(taskHandler.Payload);
-      if (payload != null)
+      if (payload is not null)
       {
         switch (payload.Type)
         {