diff --git a/.github/workflows/docker-speedup-test.yml b/.github/workflows/docker-speedup-test.yml
new file mode 100644
index 0000000000..b9f9cd5029
--- /dev/null
+++ b/.github/workflows/docker-speedup-test.yml
@@ -0,0 +1,82 @@
+
+# https://github.com/actions/starter-workflows/ci/docker-publish.yml
+# If using base images, don't forget to add READ access, eg. from a package settings page like:
+# https://github.com/orgs/storytold/packages/container/docker-base-images-rust-ssl/settings/actions_access
+name: "Speedup Test"
+on:
+  push:
+    branches:
+      - speedup-experiments
+env:
+  IMAGE_NAME: storyteller-rust-speedup-exp
+
+jobs:
+  # Push image to GitHub Packages.
+  # See also https://docs.docker.com/docker-hub/builds/
+  # See also https://depot.dev/blog/docker-layer-caching-in-github-actions
+  # See also https://evilmartians.com/chronicles/build-images-on-github-actions-with-docker-layer-caching
+  build-docker-image:
+    name: "Build Docker Image"
+    #runs-on: ubuntu-22.04 # runs-on: ubuntu-latest
+    #runs-on: github-ubuntu-16core # NB: Premium GitHub runner with more cores
+    runs-on: github-ubuntu-64core # NB: Premium GitHub runner with more cores
+    if: github.event_name == 'push'
+    permissions:
+      packages: write
+      contents: read
+
+    steps:
+      - uses: actions/checkout@v3
+
+      # - uses: docker/setup-buildx-action@v1
+      #   name: Set up Docker Buildx
+
+      - uses: docker/login-action@v1
+        name: Login to GitHub Container Registry
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }} # username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Calculate short SHA
+        id: vars
+        # echo "sha_short=$(git rev-parse --short HEAD)" >> $GITHUB_OUTPUT
+        run: |
+          echo "sha_short=$(echo ${{ github.sha }} | cut -c1-12)" >> $GITHUB_OUTPUT
+
+      - name: Emit short SHA
+        run: |
+          echo "Full SHA: ${{ github.sha }}"
+          echo "Short SHA: ${{ steps.vars.outputs.sha_short }}"
+
+      #- uses: actions/cache@v2
+      #  name: Cache Docker layers
+      #  with:
+      #    path: /tmp/.buildx-cache
+      #    key: ${{ runner.os }}-buildx-${{ github.sha }}
+      #    restore-keys: |
+      #      ${{ runner.os }}-buildx-
+
+      # Docs for this action are at https://github.com/marketplace/actions/build-docker-images-using-cache
+      - uses: whoan/docker-build-with-cache-action@v6
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }} # username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+          image_name: storytold/storyteller-rust-speedup-exp
+          dockerfile: service_cpu.Dockerfile
+          # NB: The `git_push_tag: true` option does not work as expected, so we put the sha in `image_tag`:
+          # https://github.com/whoan/docker-build-with-cache-action/issues/72
+          image_tag: speedup-${{ steps.vars.outputs.sha_short }}
+          # NB: Inject the Git SHA into the container so the servers can emit their own version:
+          build_extra_args: "--build-arg=GIT_SHA=${{ github.sha }}"
+
+
+      - name: Cleanup / Debug
+        # This job will run even on failures to help with debugging.
+        if: always()
+        run: |
+          echo "Report at final github action step:"
+          echo "Disk usage:"
+          pwd
+          du -hsc * | sort -hr