Try using cross compile instead of emulation

Dockerfile

@@ -27,7 +27,7 @@ RUN ng build --base-href=${BASE_URL}
 ##  Build Backend  ##
 #####################
 
-FROM mcr.microsoft.com/dotnet/sdk:9.0 AS build-backend
+FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/sdk:9.0 AS build-backend
 WORKDIR /src
 
 # Copy the csproj
@@ -39,8 +39,19 @@ RUN dotnet restore './MistoxWebsite.Server.csproj'
 # Copy the rest of the backend over
 COPY ./src/MistoxWebsite.Server/ ./
 
+# Get the target arch
+ARG TARGETOS TARGETARCH
+
 # Build the source
-RUN dotnet publish './MistoxWebsite.Server.csproj' -c Release -o /app/publish
+RUN if [ $TARGETARCH = "arm64" ]; then \
+        RID="arm64" \
+    elif [ "$TARGETARCHARCH" = "amd64" ]; then \
+        RID="x64" \
+    else \
+        echo "Unsupported ARCH: $ARCH" \
+        exit 1 \
+    fi \
+    dotnet publish './MistoxWebsite.Server.csproj' -c Release -r $TARGETOS-$RID -o /app/publish
 
 ################
 ##  Publish   ##