diff --git a/.github/workflows/_sandbox.yaml b/.github/workflows/_sandbox.yaml
index 7b90b72ca..376cd012a 100644
--- a/.github/workflows/_sandbox.yaml
+++ b/.github/workflows/_sandbox.yaml
@@ -1,41 +1,63 @@
-name: "~Sandbox"
-
+name: Sandbox
+run-name: CI-amd64
 on:
-  workflow_dispatch:
+  pull_request:
+    types:
+      - opened
+      - reopened
+      - ready_for_review
+      - synchronize
+    paths-ignore:
+      - "**.md"
+
+permissions:
+  contents: read # to fetch code
+  actions: write # to cancel previous workflows
+  packages: write # to upload container
 
 jobs:
-  sandbox:
-    runs-on: ubuntu-22.04
-    steps:
-      - name: Login to GitHub Container Registry
-        uses: docker/login-action@v3
-        with:
-          registry: ghcr.io
-          username: ${{ github.repository_owner }}
-          password: ${{ secrets.GITHUB_TOKEN }}
+  build-base:
+    uses: ./.github/workflows/_build_base.yaml
+    with:
+      ARCHITECTURE: amd64
+      BUILD_DATE: 20240418
+      MANIFEST_ARTIFACT_NAME: ""
+    secrets: inherit
+
+  build-jax:
+    needs: build-base
+    uses: ./.github/workflows/_build.yaml
+    with:
+      ARCHITECTURE: amd64
+      ARTIFACT_NAME: artifact-jax-build
+      BADGE_FILENAME: badge-jax-build
+      BUILD_DATE: 20240418
+      BASE_IMAGE: ${{ needs.build-base.outputs.DOCKER_TAG }}
+      CONTAINER_NAME: jax
+      DOCKERFILE: .github/container/Dockerfile.jax
+      RUNNER_SIZE: large
+    secrets: inherit
 
-      - name: Print usage
-        run: |
-          cat << EOF
-          This is an empty workflow file located in the main branch of your
-          repository. It serves as a testing ground for new GitHub Actions on
-          development branches before merging them to the main branch. By
-          defining and overloading this workflow on your development branch,
-          you can test new actions without affecting your main branch, ensuring
-          a smooth integration process once the changes are ready to be merged.
+  build-upstream-maxtext:
+    needs: build-jax
+    if: inputs.ARCHITECTURE == 'amd64' # Triton does not seem to support arm64
+    uses: ./.github/workflows/_build.yaml
+    with:
+      ARCHITECTURE: amd64
+      ARTIFACT_NAME: artifact-maxtext-build
+      BADGE_FILENAME: badge-maxtext-build
+      BUILD_DATE: 20240418
+      BASE_IMAGE: ${{ needs.build-jax.outputs.DOCKER_TAG_MEALKIT }}
+      CONTAINER_NAME: maxtext
+      DOCKERFILE: .github/container/Dockerfile.maxtext.amd64
+    secrets: inherit
 
-          Usage:
-          
-          1. In your development branch, modify the sandbox.yml workflow file
-             to include the new actions you want to test. Make sure to commit
-             the changes to the development branch.
-          2. Navigate to the 'Actions' tab in your repository, select the
-             '~Sandbox' workflow, and choose your development branch from the
-             branch dropdown menu. Click on 'Run workflow' to trigger the
-             workflow on your development branch.
-          3. Once you have tested and verified the new actions in the Sandbox
-             workflow, you can incorporate them into your main workflow(s) and
-             merge the development branch into the main branch. Remember to
-             revert the changes to the sandbox.yml file in the main branch to
-             keep it empty for future testing.
-          EOF
+  build-rosetta-maxtext:
+    needs: build-upstream-maxtext
+    uses: ./.github/workflows/_build_rosetta.yaml
+    with:
+      ARCHITECTURE: amd64
+      BUILD_DATE: 20240418
+      BASE_IMAGE: ${{ needs.build-upstream-maxtext.outputs.DOCKER_TAG_MEALKIT }}
+      BASE_LIBRARY: maxtext
+    secrets: inherit