diff --git a/backend/src/Migrations/Migrations/ClearSchemas.cs b/backend/src/Migrations/Migrations/ClearSchemas.cs
index 0088c4189..821ab8566 100644
--- a/backend/src/Migrations/Migrations/ClearSchemas.cs
+++ b/backend/src/Migrations/Migrations/ClearSchemas.cs
@@ -5,7 +5,6 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
-using System;
 using System.Threading.Tasks;
 using Squidex.Domain.Apps.Entities.Schemas.DomainObject;
 using Squidex.Infrastructure.Migrations;
diff --git a/backend/src/Squidex.Domain.Apps.Entities/Backup/RestoreGrain.cs b/backend/src/Squidex.Domain.Apps.Entities/Backup/RestoreGrain.cs
index 747d209f4..2db0782ae 100644
--- a/backend/src/Squidex.Domain.Apps.Entities/Backup/RestoreGrain.cs
+++ b/backend/src/Squidex.Domain.Apps.Entities/Backup/RestoreGrain.cs
@@ -8,7 +8,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Threading.Tasks;
 using System.Threading.Tasks.Dataflow;
 using Microsoft.Extensions.DependencyInjection;
diff --git a/backend/src/Squidex.Infrastructure/Commands/Rebuilder.cs b/backend/src/Squidex.Infrastructure/Commands/Rebuilder.cs
index f7bfc825f..8d8c5f1cc 100644
--- a/backend/src/Squidex.Infrastructure/Commands/Rebuilder.cs
+++ b/backend/src/Squidex.Infrastructure/Commands/Rebuilder.cs
@@ -85,7 +85,7 @@ namespace Squidex.Infrastructure.Commands
 
         private async Task InsertManyAsync<T, TState>(IStore<TState> store, IdSource source, CancellationToken ct = default) where T : DomainObject<TState> where TState : class, IDomainState<TState>, new()
         {
-            var parallelism = Environment.ProcessorCount * 2;
+            var parallelism = Environment.ProcessorCount;
 
             const int BatchSize = 100;
 
@@ -116,7 +116,7 @@ namespace Squidex.Infrastructure.Commands
             {
                 MaxDegreeOfParallelism = parallelism,
                 MaxMessagesPerTask = 1,
-                BoundedCapacity = parallelism * 2
+                BoundedCapacity = parallelism
             });
 
             var batchBlock = new BatchBlock<DomainId>(BatchSize, new GroupingDataflowBlockOptions
diff --git a/backend/tests/Squidex.Domain.Apps.Core.Tests/Operations/DefaultValues/DefaultValuesTests.cs b/backend/tests/Squidex.Domain.Apps.Core.Tests/Operations/DefaultValues/DefaultValuesTests.cs
index 8574b8bec..30ac33562 100644
--- a/backend/tests/Squidex.Domain.Apps.Core.Tests/Operations/DefaultValues/DefaultValuesTests.cs
+++ b/backend/tests/Squidex.Domain.Apps.Core.Tests/Operations/DefaultValues/DefaultValuesTests.cs
@@ -5,7 +5,6 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
-using System.Collections.Generic;
 using NodaTime;
 using Squidex.Domain.Apps.Core.Apps;
 using Squidex.Domain.Apps.Core.Contents;