diff --git a/.github/workflows/post-release-push-images.yml b/.github/workflows/post-release-push-images.yml
index 145ebfdf2..818b5fff9 100644
--- a/.github/workflows/post-release-push-images.yml
+++ b/.github/workflows/post-release-push-images.yml
@@ -17,16 +17,22 @@ jobs:
           token: ${{ secrets.GITHUB_TOKEN }}
           persist-credentials: true
 
+      - name: Set up QEMU (for multi-arch builds)
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
       - name: Log in to Docker Hub
-        uses: docker/login-action@v2
+        uses: docker/login-action@v3
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
 
-      # All-in-one Image Steps
+      # All-in-one Image Steps (multi-arch: amd64 + arm64)
       - name: Extract metadata (tags, labels) for All-in-one Docker
         id: meta_all_in_one
-        uses: docker/metadata-action@v3
+        uses: docker/metadata-action@v5
         with:
           images: daveearley/hi.events-all-in-one
           tags: |
@@ -34,13 +40,16 @@ jobs:
             type=raw,value=latest,enable=${{ github.event.release.prerelease == false }}
 
       - name: Build and push All-in-one Docker image
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v5
         with:
           context: ./
           file: ./Dockerfile.all-in-one
+          platforms: linux/amd64,linux/arm64
           push: true
           tags: ${{ steps.meta_all_in_one.outputs.tags }}
           labels: ${{ steps.meta_all_in_one.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
 
       # Backend Image Steps
       - name: Extract metadata (tags, labels) for Backend Docker
diff --git a/Dockerfile.all-in-one b/Dockerfile.all-in-one
index c5377aa15..8e5ff472a 100644
--- a/Dockerfile.all-in-one
+++ b/Dockerfile.all-in-one
@@ -4,19 +4,26 @@ WORKDIR /app/frontend
 
 RUN apk add --no-cache yarn
 
+# Increase network timeout for slow ARM emulation builds
+RUN yarn config set network-timeout 600000
+
 COPY ./frontend/package.json ./frontend/yarn.lock ./
 
 COPY ./frontend .
 
-RUN yarn install && yarn build
+RUN yarn install --network-timeout 600000 --frozen-lockfile && yarn build
 
-FROM serversideup/php:beta-8.3.2-fpm-alpine
+# Use stable multi-arch serversideup/php image
+FROM serversideup/php:8.3-fpm-alpine
 
 ENV PHP_OPCACHE_ENABLE=1
 
+# Switch to root for installing extensions and packages
+USER root
+
 RUN install-php-extensions intl
 
-RUN apk add --no-cache nodejs yarn nginx supervisor
+RUN apk add --no-cache nodejs yarn nginx supervisor dos2unix
 
 COPY --from=node-frontend /app/frontend /app/frontend