diff --git a/backend/src/Squidex.Domain.Apps.Entities/DomainObjectState.cs b/backend/src/Squidex.Domain.Apps.Entities/DomainObjectState.cs
index 3578b072a..83c55edbf 100644
--- a/backend/src/Squidex.Domain.Apps.Entities/DomainObjectState.cs
+++ b/backend/src/Squidex.Domain.Apps.Entities/DomainObjectState.cs
@@ -69,13 +69,15 @@ namespace Squidex.Domain.Apps.Entities
                 clone.Id = headers.AggregateId();
             }
 
+            var timestamp = headers.Timestamp();
+
             if (clone.CreatedBy == null)
             {
-                clone.Created = headers.Timestamp();
+                clone.Created = timestamp;
                 clone.CreatedBy = payload.Actor;
             }
 
-            clone.LastModified = headers.Timestamp();
+            clone.LastModified = timestamp;
             clone.LastModifiedBy = payload.Actor;
 
             return (clone as T)!;
diff --git a/backend/src/Squidex.Infrastructure.MongoDb/EventSourcing/StreamPosition.cs b/backend/src/Squidex.Infrastructure.MongoDb/EventSourcing/StreamPosition.cs
index dcfb32884..81e9e8fd8 100644
--- a/backend/src/Squidex.Infrastructure.MongoDb/EventSourcing/StreamPosition.cs
+++ b/backend/src/Squidex.Infrastructure.MongoDb/EventSourcing/StreamPosition.cs
@@ -5,6 +5,7 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
+using System.Text;
 using MongoDB.Bson;
 
 namespace Squidex.Infrastructure.EventSourcing
@@ -34,15 +35,17 @@ namespace Squidex.Infrastructure.EventSourcing
 
         public static implicit operator string(StreamPosition position)
         {
-            var parts = new object[]
-            {
-                position.Timestamp.Timestamp,
-                position.Timestamp.Increment,
-                position.CommitOffset,
-                position.CommitSize
-            };
+            var sb = new StringBuilder();
+
+            sb.Append(position.Timestamp.Timestamp);
+            sb.Append(",");
+            sb.Append(position.Timestamp.Increment);
+            sb.Append(",");
+            sb.Append(position.CommitOffset);
+            sb.Append(",");
+            sb.Append(position.CommitSize);
 
-            return string.Join("-", parts);
+            return sb.ToString();
         }
 
         public static implicit operator StreamPosition(string? position)
diff --git a/backend/src/Squidex.Infrastructure.MongoDb/MongoDb/BsonHelper.cs b/backend/src/Squidex.Infrastructure.MongoDb/MongoDb/BsonHelper.cs
index 578683590..dc6c45fb4 100644
--- a/backend/src/Squidex.Infrastructure.MongoDb/MongoDb/BsonHelper.cs
+++ b/backend/src/Squidex.Infrastructure.MongoDb/MongoDb/BsonHelper.cs
@@ -9,13 +9,26 @@ namespace Squidex.Infrastructure.MongoDb
 {
     public static class BsonHelper
     {
+        private const string TypeBson = "§type";
+        private const string TypeJson = "$json";
+
         public static string UnescapeBson(this string value)
         {
+            if (value == TypeBson)
+            {
+                return TypeJson;
+            }
+
             return ReplaceFirstCharacter(value, '§', '$');
         }
 
         public static string EscapeJson(this string value)
         {
+            if (value == TypeJson)
+            {
+                return TypeBson;
+            }
+
             return ReplaceFirstCharacter(value, '$', '§');
         }
 
diff --git a/backend/src/Squidex.Infrastructure/Json/Newtonsoft/NamedStringIdConverter.cs b/backend/src/Squidex.Infrastructure/Json/Newtonsoft/NamedStringIdConverter.cs
index e5014a77d..aa45e976c 100644
--- a/backend/src/Squidex.Infrastructure/Json/Newtonsoft/NamedStringIdConverter.cs
+++ b/backend/src/Squidex.Infrastructure/Json/Newtonsoft/NamedStringIdConverter.cs
@@ -29,9 +29,9 @@ namespace Squidex.Infrastructure.Json.Newtonsoft
             return result;
         }
 
-        private static bool ParseString(string value, out string result)
+        private static bool ParseString(ReadOnlySpan<char> value, out string result)
         {
-            result = value;
+            result = new string(value);
 
             return true;
         }
diff --git a/backend/src/Squidex.Infrastructure/Language.cs b/backend/src/Squidex.Infrastructure/Language.cs
index f4497c89a..1b5dd27a2 100644
--- a/backend/src/Squidex.Infrastructure/Language.cs
+++ b/backend/src/Squidex.Infrastructure/Language.cs
@@ -56,14 +56,14 @@ namespace Squidex.Infrastructure
 
         public static bool IsValidLanguage(string iso2Code)
         {
-            Guard.NotNullOrEmpty(iso2Code);
+            Guard.NotNull(iso2Code);
 
             return AllLanguagesField.ContainsKey(iso2Code);
         }
 
         public static bool TryGetLanguage(string iso2Code, [MaybeNullWhen(false)] out Language language)
         {
-            Guard.NotNullOrEmpty(iso2Code);
+            Guard.NotNull(iso2Code);
 
             return AllLanguagesField.TryGetValue(iso2Code, out language!);
         }
diff --git a/backend/src/Squidex.Infrastructure/NamedId{T}.cs b/backend/src/Squidex.Infrastructure/NamedId{T}.cs
index f32893219..5ab243df4 100644
--- a/backend/src/Squidex.Infrastructure/NamedId{T}.cs
+++ b/backend/src/Squidex.Infrastructure/NamedId{T}.cs
@@ -12,7 +12,7 @@ using System.Diagnostics.CodeAnalysis;
 
 namespace Squidex.Infrastructure
 {
-    public delegate bool Parser<T>(string input, out T result);
+    public delegate bool Parser<T>(ReadOnlySpan<char> input, out T result);
 
     [Equals(DoNotAddEqualityOperators = true)]
     public sealed class NamedId<T> where T : notnull
@@ -42,11 +42,13 @@ namespace Squidex.Infrastructure
         {
             if (value != null)
             {
+                var span = value.AsSpan();
+
                 if (typeof(T) == typeof(Guid))
                 {
                     if (value.Length > GuidLength + 1 && value[GuidLength] == ',')
                     {
-                        if (parser(value.Substring(0, GuidLength), out var id))
+                        if (parser(span.Slice(0, GuidLength), out var id))
                         {
                             result = new NamedId<T>(id, value.Substring(GuidLength + 1));
 
@@ -60,7 +62,7 @@ namespace Squidex.Infrastructure
 
                     if (index > 0 && index < value.Length - 1)
                     {
-                        if (parser(value.Substring(0, index), out var id))
+                        if (parser(span.Slice(0, index), out var id))
                         {
                             result = new NamedId<T>(id, value.Substring(index + 1));