diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 24d07ec..8f4f9c1 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -14,7 +14,7 @@ jobs:
     if: (github.event_name == 'pull_request' && github.event.action != 'closed')
     runs-on: windows-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           submodules: true
       - name: Publish Frontend
@@ -28,16 +28,12 @@ jobs:
           Compress-Archive temp/api/** temp/api.zip;
           Remove-Item -Recurse -Force temp/frontend
           Remove-Item -Recurse -Force temp/api
-      - name: Add Artifact App
-        uses: actions/upload-artifact@v3
+          Copy-Item ./build/deploy.ps1 temp/deploy.ps1
+      - name: Add Artifact
+        uses: actions/upload-artifact@v4
         with:
           name: artifact
           path: temp/
-      - name: Add Artifact script
-        uses: actions/upload-artifact@v3
-        with:
-          name: artifact
-          path: ./build/deploy.ps1
   deploy_job:
     if: (github.event_name == 'pull_request' && github.event.action != 'closed')
     runs-on: ubuntu-latest
@@ -51,7 +47,7 @@ jobs:
       pull-requests: write
     name: Deploy Job
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           submodules: true
       - name: compile bicep
@@ -97,7 +93,7 @@ jobs:
     runs-on: ubuntu-latest
     name: Close Pull Request Job
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           submodules: true
       - name: Get PR title
diff --git a/global.json b/global.json
index e23437b..04f5d2c 100644
--- a/global.json
+++ b/global.json
@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "7.0.100",
+    "version": "9.0.303",
     "rollForward": "latestMajor"
   }
 }
diff --git a/src/CZ.Azure.FileExchange.Api/AddMetadata.cs b/src/CZ.Azure.FileExchange.Api/AddMetadata.cs
index ba89fc8..44b9281 100644
--- a/src/CZ.Azure.FileExchange.Api/AddMetadata.cs
+++ b/src/CZ.Azure.FileExchange.Api/AddMetadata.cs
@@ -35,7 +35,7 @@ public async Task<HttpResponseData> Run(
         var events = EventGridEvent.ParseMany(eventsRaw);
         var relevantChangeTierEvents = events.Where(e =>
             e.EventType == BlobChanged &&
-            e.Data.ToObjectFromJson<BlobTierChangeEvent>().api == SetBlobTier
+            e.Data.ToObjectFromJson<BlobTierChangeEvent>()?.api == SetBlobTier
             );
 
         var relevantValidationEvents = events.Where(e =>
@@ -47,13 +47,16 @@ public async Task<HttpResponseData> Run(
             foreach (var tierChangedEvent in relevantChangeTierEvents)
             {
                 var data = tierChangedEvent.Data.ToObjectFromJson<BlobTierChangeEvent>();
+                if (data?.url == null) continue;
+                
                 var blobUri = new Uri(data.url);
                 var containerName = blobUri.Segments.Skip(1).First()[..^1];
                 var containerClient = blobService.GetBlobContainerClient(containerName);
                 var blobClient = containerClient.GetBlobClient(blobUri.Segments.Last());
-                await blobClient.SetMetadataAsync(new Dictionary<string, string>() {
+                await blobClient.SetMetadataAsync(new Dictionary<string, string>
+                {
                      // That is important to change the 'x-ms-last-access-time'
-                    { "lastTimeRetrieved", tierChangedEvent.EventTime.ToString(CultureInfo.CurrentCulture)}
+                    ["lastTimeRetrieved"] = tierChangedEvent.EventTime.ToString(CultureInfo.CurrentCulture)
                 });
             }
         }
@@ -92,20 +95,20 @@ private static string GetEnvironmentVariable(string name) =>
 
     public class BlobTierChangeEvent
     {
-        public string api { get; set; }
-        public string requestId { get; set; }
-        public string eTag { get; set; }
-        public string contentType { get; set; }
+        public required string api { get; set; }
+        public required string requestId { get; set; }
+        public required string eTag { get; set; }
+        public required string contentType { get; set; }
         public int contentLength { get; set; }
-        public string blobType { get; set; }
-        public string url { get; set; }
-        public string sequencer { get; set; }
-        public Storagediagnostics storageDiagnostics { get; set; }
+        public required string blobType { get; set; }
+        public required string url { get; set; }
+        public required string sequencer { get; set; }
+        public required Storagediagnostics storageDiagnostics { get; set; }
     }
 
     public class Storagediagnostics
     {
-        public string batchId { get; set; }
+        public required string batchId { get; set; }
     }
 
 }
diff --git a/src/CZ.Azure.FileExchange.Api/CZ.Azure.FileExchange.Api.csproj b/src/CZ.Azure.FileExchange.Api/CZ.Azure.FileExchange.Api.csproj
index abba096..c95baff 100644
--- a/src/CZ.Azure.FileExchange.Api/CZ.Azure.FileExchange.Api.csproj
+++ b/src/CZ.Azure.FileExchange.Api/CZ.Azure.FileExchange.Api.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <AzureFunctionsVersion>v4</AzureFunctionsVersion>
     <OutputType>Exe</OutputType>
     <ImplicitUsings>enable</ImplicitUsings>
@@ -8,17 +8,17 @@
     <UserSecretsId>84a717a7-ef76-47be-9101-2a62e74fd7d3</UserSecretsId>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Azure.Messaging.EventGrid" Version="4.14.1" />
-    <PackageReference Include="Azure.Storage.Blobs" Version="12.15.1" />
-    <PackageReference Include="Azure.Storage.Files.Shares" Version="12.13.1" />
-    <PackageReference Include="Azure.Storage.Queues" Version="12.13.1" />
-    <PackageReference Include="Microsoft.Azure.Functions.Worker" Version="1.13.0" />
-    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http" Version="3.0.13" />
+    <PackageReference Include="Azure.Messaging.EventGrid" Version="4.28.0" />
+    <PackageReference Include="Azure.Storage.Blobs" Version="12.23.0" />
+    <PackageReference Include="Azure.Storage.Files.Shares" Version="12.21.0" />
+    <PackageReference Include="Azure.Storage.Queues" Version="12.21.0" />
+    <PackageReference Include="Microsoft.Azure.Functions.Worker" Version="2.0.0" />
+    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http" Version="3.2.0" />
     <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.OpenApi" Version="1.5.1" />
-    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Storage" Version="5.0.1" />
-    <PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="1.9.0" />
-    <PackageReference Include="Microsoft.Extensions.Azure" Version="1.6.3" />
-    <PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="7.0.0" />
+    <PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Storage" Version="6.7.0" />
+    <PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="1.18.1" />
+    <PackageReference Include="Microsoft.Extensions.Azure" Version="1.10.0" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="9.0.0" />
   </ItemGroup>
   <ItemGroup>
     <None Update="host.json">
diff --git a/src/CZ.Azure.FileExchange/CZ.Azure.FileExchange.csproj b/src/CZ.Azure.FileExchange/CZ.Azure.FileExchange.csproj
index 31c09cb..5deea32 100644
--- a/src/CZ.Azure.FileExchange/CZ.Azure.FileExchange.csproj
+++ b/src/CZ.Azure.FileExchange/CZ.Azure.FileExchange.csproj
@@ -1,35 +1,25 @@
 <Project Sdk="Microsoft.NET.Sdk.BlazorWebAssembly">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="DartSassBuilder" Version="0.3.0-beta" />
-    <PackageReference Include="Azure.Storage.Blobs" Version="12.14.1" />
-    <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly" Version="7.0.1" />
-    <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.DevServer" Version="7.0.1" PrivateAssets="all" />
+    <!-- <PackageReference Include="DartSassBuilder" Version="1.1.0" /> -->
+    <PackageReference Include="Azure.Storage.Blobs" Version="12.23.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly" Version="9.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.DevServer" Version="9.0.0" PrivateAssets="all" />
   </ItemGroup>
 
-  <!-- SASS options -->
-  <PropertyGroup>
-    <!-- outputstyle option -->
-    <DartSassOutputStyle>compressed</DartSassOutputStyle>
-    <DartSassOutputStyle Condition="'$(Configuration)' == 'Debug'">expanded</DartSassOutputStyle>
-    <!-- level option -->
-    <DartSassOutputLevel>verbose</DartSassOutputLevel>
-    <!-- msbuild output level -->
-    <DartSassMessageLevel>High</DartSassMessageLevel>
-  </PropertyGroup>
-  <ItemGroup>
-    <!-- add files manually -->
-    <SassFile Include="Client/**/*.scss" />
-  </ItemGroup>
-
-  <Target Name="copy_sass_to_the_right_place" AfterTargets="DartSass_Build">
-    <Copy SourceFiles="Client/styles/main.css" DestinationFolder="wwwroot/client/" />
+  <!-- Custom SASS compilation using native sass command -->
+  <Target Name="CompileSass" BeforeTargets="Build">
+    <Exec Command="sass Client/styles/main.scss Client/styles/main.css --style=expanded" 
+          ContinueOnError="false" 
+          WorkingDirectory="$(MSBuildProjectDirectory)" />
+    <Copy SourceFiles="$(MSBuildProjectDirectory)/Client/styles/main.css" 
+          DestinationFolder="$(MSBuildProjectDirectory)/wwwroot/client/" />
   </Target>
 
 </Project>
\ No newline at end of file
diff --git a/src/CZ.Azure.FileExchange/Client/styles/main.css.map b/src/CZ.Azure.FileExchange/Client/styles/main.css.map
new file mode 100644
index 0000000..00a5276
--- /dev/null
+++ b/src/CZ.Azure.FileExchange/Client/styles/main.css.map
@@ -0,0 +1 @@
+{"version":3,"sourceRoot":"","sources":["vendors/_cssgg.scss","abstracts/_variables.scss","base/_reset.scss","base/_base.scss","base/_typography.scss","layout/_header.scss","layout/_navigation.scss","layout/_main.scss","components/_blazor-error.scss","components/_blazor-splash.scss","components/_button.scss","abstracts/_mixins.scss","components/_input-text.scss","pages/_index.scss","pages/_download.scss"],"names":[],"mappings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nMR;EACI;EACA;EACA;EACA;EACA;EACA;EACA;EACA;;;ACjCH;AAAA;AAAA;EAGG;EACA;EACA;EACA;EACA;;;ACJJ;AAAA;EAEI;EACA;;;AAGJ;EACI,aCTG;EDUH;EACA;EACA;EACA,YFdS;;;AIEb;EACI;;AAEA;EACI;EACA,aJSM;EIRN;EACA;EACA;EACA;EACA;;;ACVR;EACI;EACA;EACA;;AAEA;EACI;EACA;EACA,aLMM;EKLN;EACA;EACA;;AAEA;EACI,QLOE;;;AMvBd;EACI;EACA;EACA;EACA;;AAEA;EACI;EACA;;;ACRP;EACG;EACA;EACA;EACA;EACA;EACA;EACA;EACA;EACA;;AAEA;EACI;EACA;EACA;EACA;;;AAKR;EACI;EACA;EACA;;AAEA;EACI;;;ACxBR;AAII;EACI;EACA;EACA,aROM;EQNN;EACA;EACA;EACA,QRUM;;;AQNd;ACdA;EACI;EACA;EACA;EACA;;;AAGJ;EACI;EACA;ECTA;EACA;EACA;EACA;EACA;EACA;EDMA;EACA;EACA;EACA,aTDU;ESEV;EACA;EACA;EAEA;;AAEA;EACI;;AAEJ;EACI;;AAGJ;EACI;EACA;;;AE9BR;EACI;EACA;EACA;;;AAGJ;EDNI;EACA;EACA;EACA;EACA;EACA;ECGA;EACA;EACA;EACA;;AAEA;EACI;EACA,kBXfU;;;AYChB;EFDE;EACA;EACA;EACA;EACA;EACA;EEFA;;AAEA;EACE;EACA,aZMQ;;AYHV;EACE;EACA;EACA;EACA;;AAEA;EACE,kBZZY;;AYed;EACE;;AAMN;EACE;EACA;;AAEA;EACE;EACA;EACA;EACA;EACA;EACA;EFrCF;EACA;EACA;EACA;EACA;EACA;EEmCE;;AAEA;EACE;;AAGF;EACE;EACA;;AAIJ;EACE;EACA;EACA;EACA;EACA;EACA;EACA;EACA;;AAEA;EACE;EACA;;AAGF;EACE;;AAGF;EACI;;AAKR;EACE;EACA;EACA;;AAEA;EACE;;AAGE;EACE;;AAGF;EACE;;AAIJ;EACE;EACA;EACA;EACA;EACA;EACA;EACA;EACA;EACA;EACA;;AAEA;EACE;;AAGF;EACE;EACA;;AAIJ;EFrHF;EACA;EACA;EACA;EACA;EACA;EEkHI;EACA;EACA;EACA;EACA;EACA;EACA;;AAEA;EACE;;AAGF;EACE;EACA;EACA;EACA;EACA;;AAEA;EACE;EACA;EACA;EACA;EACA;EACA;EACA;EACA;;AAIJ;EACE;EACA;EACA;;AAEA;EACE;;;AC3JZ;EACI;EHFA;EACA;EACA;EACA;EACA;EACA;EGAA;;AAGJ;EACI;EACA;EACA;;AAEA;EHbA;EACA;EACA;EACA;EACA;EACA;EGUI;EACA;EACA;EACA;EACA;EACA;;AAEA;EACI;;AAIJ;EACI;EACA;;AAEA;EACI;EACA,ObhCO;;AakCP;EACI","file":"main.css"}
\ No newline at end of file
diff --git a/src/CZ.Azure.FileExchange/Pages/Download.razor.cs b/src/CZ.Azure.FileExchange/Pages/Download.razor.cs
index 0c051f2..ce182bb 100644
--- a/src/CZ.Azure.FileExchange/Pages/Download.razor.cs
+++ b/src/CZ.Azure.FileExchange/Pages/Download.razor.cs
@@ -1,11 +1,37 @@
 namespace CZ.Azure.FileExchange.Pages;
 using global::Azure.Storage.Blobs;
 using global::Azure.Storage.Blobs.Models;
+using Microsoft.Extensions.Logging;
 
 public partial class Download
 {
+    // High-performance logging using LoggerMessage
+    private static readonly Action<ILogger, string, AccessTier?, Exception?> LogBlobNotInArchive =
+        LoggerMessage.Define<string, AccessTier?>(
+            LogLevel.Warning,
+            new EventId(1, nameof(LogBlobNotInArchive)),
+            "User tried to retrieve a blob from archive, but the blob was not in the archive tier. The blob: '{BlobName}', tier: '{AccessTier}'");
+
+    private static readonly Action<ILogger, string, string?, Exception?> LogBlobRetrievalStatus =
+        LoggerMessage.Define<string, string?>(
+            LogLevel.Warning,
+            new EventId(2, nameof(LogBlobRetrievalStatus)),
+            "The blob '{BlobName}' can't be retrieved because the status is {ArchiveStatus}.");
+
+    private static readonly Action<ILogger, string, Exception?> LogMultipleBlobsFound =
+        LoggerMessage.Define<string>(
+            LogLevel.Warning,
+            new EventId(3, nameof(LogMultipleBlobsFound)),
+            "The blob '{BlobName}' exist more then ones. 🫨");
+
+    private static readonly Action<ILogger, string, Exception?> LogBlobNotFound =
+        LoggerMessage.Define<string>(
+            LogLevel.Warning,
+            new EventId(4, nameof(LogBlobNotFound)),
+            "The blob '{BlobName}' doesn't exist. 🫨");
+
     private string Code { get; set; } = string.Empty;
-    private readonly List<BlobItem> blobs = new();
+    private readonly List<BlobItem> blobs = [];
     private Uri? sasUrl;
     private async Task LoadFiles()
     {
@@ -51,9 +77,7 @@ private async Task StartRetrivalFromArchive(string blobName)
 
         if (blob.Properties.AccessTier != AccessTier.Archive)
         {
-            this.logger.LogWarning($"User tried to retrieve a blob from archive, " +
-            $"but the blob was not in the archive tier." +
-            $"The blob: '{blob.Name}', tier: '{blob.Properties.AccessTier}'");
+            LogBlobNotInArchive(this.logger, blob.Name, blob.Properties.AccessTier, null);
             /// TODO: make a user visible message that a not archived blob can't be retrieved
             return;
         }
@@ -65,8 +89,7 @@ private async Task StartRetrivalFromArchive(string blobName)
             string.Equals(blobProperties.Value.ArchiveStatus, "rehydrate-pending-to-cool", StringComparison.OrdinalIgnoreCase)
         )
         {
-            this.logger.LogWarning($"The blob '{blob.Name}' can't be retrieved because the " +
-            $"status is {blobProperties.Value.ArchiveStatus}.");
+            LogBlobRetrievalStatus(this.logger, blob.Name, blobProperties.Value.ArchiveStatus, null);
             /// TODO: make a user visible message that the blob can't be double retrieved
             /// and return
         }
@@ -81,7 +104,7 @@ private async Task StartRetrivalFromArchive(string blobName)
                 if (foundBlobs > 0)
                 {
                     // TODO: something weird happend. We found for our blob we are looking for, more then one real blob.
-                    this.logger.LogWarning($"The blob '{blobName}' exist more then ones. 🫨");
+                    LogMultipleBlobsFound(this.logger, blobName, null);
                 }
                 this.blobs[blobListEntryLocation] = updatedBlob;
             }
@@ -89,7 +112,7 @@ private async Task StartRetrivalFromArchive(string blobName)
         else
         {
             //TODO: some odd state happend. We change the state of the blob but we can't find it in our blobs list
-            this.logger.LogWarning($"The blob '{blobName}' doesn't exist. 🫨");
+            LogBlobNotFound(this.logger, blobName, null);
         }
 
 
diff --git a/src/CZ.Azure.FileExchange/Pages/Index.razor.cs b/src/CZ.Azure.FileExchange/Pages/Index.razor.cs
index fb0989b..0934c11 100644
--- a/src/CZ.Azure.FileExchange/Pages/Index.razor.cs
+++ b/src/CZ.Azure.FileExchange/Pages/Index.razor.cs
@@ -10,9 +10,9 @@ public partial class Index
     [Inject]
     private HttpClient Http { get; set; } = default!;
 
-    private readonly List<File> files = new();
+    private readonly List<File> files = [];
     private Uri? sasUrl;
-    private readonly IList<string> fileInputs = new List<string>() { Guid.NewGuid().ToString() };
+    private readonly List<string> fileInputs = [Guid.NewGuid().ToString()];
     private bool isDragHover;
 
     public string? SasId => this.sasUrl?.AbsolutePath?.Replace("/", "");
@@ -78,7 +78,7 @@ private Task DeleteFile(File file)
         return Task.CompletedTask;
     }
 
-    private class File
+    private sealed class File
     {
         public File(string name, IBrowserFile browserFile, long processedSize = 0)
         {
@@ -93,7 +93,7 @@ public File(string name, IBrowserFile browserFile, long processedSize = 0)
         public long ProcessedSize { get; set; }
     }
 
-    private class ProgressHandler : IProgress<long>
+    private sealed class ProgressHandler : IProgress<long>
     {
         private readonly Index pageRef;
         private readonly File file;