diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9fe0c628da5..0dcbf60c453 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,6 @@ on:
       - '**/Cargo.toml'
       - '**/Cargo.lock'
       - '**/deny.toml'
-      - 'docker/**'
       - '.github/workflows/ci.yml'
 
 env:
diff --git a/.github/workflows/coverage.patch.yml b/.github/workflows/coverage.patch.yml
index d3961267ed0..2896ae3a3a9 100644
--- a/.github/workflows/coverage.patch.yml
+++ b/.github/workflows/coverage.patch.yml
@@ -1,7 +1,6 @@
 name: Coverage
 
 on:
-  workflow_dispatch:
   pull_request:
     paths-ignore:
       - '**/*.rs'
diff --git a/.github/workflows/docs.patch.yml b/.github/workflows/docs.patch.yml
deleted file mode 100644
index 5dea8d9af5a..00000000000
--- a/.github/workflows/docs.patch.yml
+++ /dev/null
@@ -1,21 +0,0 @@
-name: Docs
-
-on:
-  workflow_dispatch:
-  push:
-    branches:
-      - main
-    paths-ignore:
-      - 'book/**'
-      - '**/firebase.json'
-      - 'katex-header.html'
-      - '.github/workflows/docs.yml'
-
-jobs:
-  build:
-    name: Build and Deploy Docs (+beta)
-    timeout-minutes: 30
-    runs-on: ubuntu-latest
-
-    steps:
-      - run: 'echo "No build required"'
diff --git a/.github/workflows/regenerate-stateful-test-disks.yml b/.github/workflows/regenerate-stateful-test-disks.yml
deleted file mode 100644
index 2db517c2636..00000000000
--- a/.github/workflows/regenerate-stateful-test-disks.yml
+++ /dev/null
@@ -1,70 +0,0 @@
-name: Regenerate test state
-
-on:
-  workflow_dispatch:
-    inputs:
-      network:
-        default: 'mainnet'
-
-env:
-  PROJECT_ID: ${{ secrets.GCP_PROJECT_ID }}
-  ZONE: europe-west1-b
-  MACHINE_TYPE: n2-standard-4
-  DEPLOY_SA: cos-vm@${{ secrets.GCP_PROJECT_ID }}.iam.gserviceaccount.com
-
-jobs:
-
-  regenerate:
-    name: Regenerate test state
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2.4.0
-        with:
-          persist-credentials: false
-
-      - name: Inject slug/short variables
-        uses: rlespinasse/github-slug-action@v4
-
-      - name: Set up gcloud
-        uses: google-github-actions/setup-gcloud@v0.5.0
-        with:
-          project_id: ${{ env.PROJECT_ID }}
-          service_account_key: ${{ secrets.GCLOUD_AUTH }}
-
-      # Creates Compute Engine virtual machine instance w/ disks
-      - name: Create instance
-        run: |
-          gcloud compute instances create-with-container "zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_SHA_SHORT }}" \
-          --boot-disk-size 100GB \
-          --boot-disk-type pd-ssd \
-          --container-image rust:buster \
-          --container-mount-disk mount-path='/${{ github.event.inputs.network }}',name="zebrad-cache-${{ env.GITHUB_SHA_SHORT }}-${{ github.event.inputs.network }}-canopy" \
-          --container-restart-policy never \
-          --create-disk name="zebrad-cache-${{ env.GITHUB_SHA_SHORT }}-${{ github.event.inputs.network }}-canopy",size=100GB,type=pd-balanced \
-          --machine-type ${{ env.MACHINE_TYPE }} \
-          --service-account ${{ env.DEPLOY_SA }} \
-          --scopes cloud-platform \
-          --tags zebrad \
-          --zone "${{ env.ZONE }}"
-      # Build and run test container to sync up to activation and no further
-      - name: Regenerate state for tests
-        id: regenerate-state
-        run: |
-          gcloud compute ssh "zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_SHA_SHORT }}" --zone "${{ env.ZONE }}" --command \
-          "git clone -b ${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }} https://github.com/ZcashFoundation/zebra.git &&
-          cd zebra/ &&
-          docker build --build-arg SHORT_SHA=${{ env.GITHUB_SHA_SHORT }} -f docker/Dockerfile.test -t zebrad-test . &&
-          docker run -i -e "ZEBRA_SKIP_IPV6_TESTS=1" --mount type=bind,source=/mnt/disks/gce-containers-mounts/gce-persistent-disks/zebrad-cache-${{ env.GITHUB_SHA_SHORT }}-${{ github.event.inputs.network }}-canopy,target=/zebrad-cache zebrad-test:latest cargo test --verbose --features test_sync_to_mandatory_checkpoint_${{ github.event.inputs.network }} --manifest-path zebrad/Cargo.toml sync_to_mandatory_checkpoint_${{ github.event.inputs.network }};
-          "
-      # Create image from disk that will be used in test.yml workflow
-      - name: Create image from state disk
-        # Only run if the earlier step succeeds
-        if: steps.regenerate-state.outcome == 'success'
-        run: |
-          gcloud compute images create "zebrad-cache-${{ env.GITHUB_SHA_SHORT }}-${{ github.event.inputs.network }}-canopy" --source-disk="zebrad-cache-${{ env.GITHUB_SHA_SHORT }}-${{ github.event.inputs.network }}-canopy" --source-disk-zone="${{ env.ZONE }}"
-      # Clean up
-      - name: Delete test instance
-        # Always run even if the earlier step fails
-        if: ${{ always() }}
-        run: |
-          gcloud compute instances delete "zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_SHA_SHORT }}" --delete-disks all --zone "${{ env.ZONE }}"
diff --git a/.github/workflows/test.patch.yml b/.github/workflows/test.patch.yml
deleted file mode 100644
index 9918e6e3cfd..00000000000
--- a/.github/workflows/test.patch.yml
+++ /dev/null
@@ -1,22 +0,0 @@
-name: Test
-
-on:
-  workflow_dispatch:
-  push:
-    branches:
-      - main
-    paths-ignore:
-      - '**/*.rs'
-      - '**/*.txt'
-      - '**/Cargo.toml'
-      - '**/Cargo.lock'
-      - 'docker/**'
-      - '.github/workflows/test.yml'
-
-jobs:
-  test:
-    name: Run all tests
-    runs-on: ubuntu-latest
-
-    steps:
-      - run: 'echo "No build required"'
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f99dabdc996..fca0dc727ce 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -2,7 +2,14 @@ name: Test
 
 on:
   workflow_dispatch:
-  push:
+    inputs:
+      network:
+        default: 'Mainnet'
+      regenerate-disks:
+        type: boolean
+        default: false
+        description: Just update stateful disks
+  pull_request:
     branches:
       - main
     paths:
@@ -14,59 +21,375 @@ on:
       - '.github/workflows/test.yml'
 
 env:
+  CARGO_INCREMENTAL: '1'
+  ZEBRA_SKIP_IPV6_TESTS: "1"
+  NETWORK: Mainnet
   PROJECT_ID: ${{ secrets.GCP_PROJECT_ID }}
-  ZONE: europe-west1-b
-  MACHINE_TYPE: n2-standard-8
-  DEPLOY_SA: cos-vm@${{ secrets.GCP_PROJECT_ID }}.iam.gserviceaccount.com
+  GAR_BASE: us-docker.pkg.dev/${{ secrets.GCP_PROJECT_ID }}/zebra
+  GCR_BASE: gcr.io/${{ secrets.GCP_PROJECT_ID }}
+  REGION: us-central1
+  ZONE: us-central1-a
+  MACHINE_TYPE: c2-standard-8
+  IMAGE_NAME: zebrad-test
 
 jobs:
+  build:
+    name: Build images
+    timeout-minutes: 210
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2.4.0
+        with:
+          persist-credentials: false
+
+      - name: Inject slug/short variables
+        uses: rlespinasse/github-slug-action@v4
+
+      # Setup Docker Buildx to allow use of docker cache layers from GH
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+        with:
+          driver-opts: network=host
+
+      - name: Login to Google Artifact Registry
+        uses: docker/login-action@v1.12.0
+        with:
+          registry: us-docker.pkg.dev
+          username: _json_key
+          password: ${{ secrets.GOOGLE_CREDENTIALS }}
+
+      - name: Login to Google Container Registry
+        uses: docker/login-action@v1.12.0
+        with:
+          registry: gcr.io
+          username: _json_key
+          password: ${{ secrets.GOOGLE_CREDENTIALS }}
+
+      # Build and push image to Google Artifact Registry
+      - name: Build & push
+        id: docker_build
+        uses: docker/build-push-action@v2.8.0
+        with:
+          target: tester
+          context: .
+          file: ./docker/Dockerfile.build
+          tags: |
+            ${{ env.GAR_BASE }}/${{ env.IMAGE_NAME }}:latest
+            ${{ env.GAR_BASE }}/${{ env.IMAGE_NAME }}:${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}
+            ${{ env.GCR_BASE }}/${{ env.GITHUB_REPOSITORY_SLUG_URL }}/${{ env.IMAGE_NAME }}:latest
+            ${{ env.GCR_BASE }}/${{ env.GITHUB_REPOSITORY_SLUG_URL }}/${{ env.IMAGE_NAME }}:${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}
+          build-args: |
+            NETWORK=${{ github.event.inputs.network || env.NETWORK }}
+            SHORT_SHA=${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}
+            RUST_BACKTRACE=full
+            ZEBRA_SKIP_NETWORK_TESTS="1"
+            CHECKPOINT_SYNC=${{ github.event.inputs.checkpoint_sync || true }}
+            RUST_LOG=debug
+            SENTRY_DSN=${{ secrets.SENTRY_ENDPOINT }}
+          push: true
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+  test-all:
+    name: Test all
+    runs-on: ubuntu-latest
+    needs: build
+    if: ${{ github.event.inputs.regenerate-disks != 'true' }}
+    steps:
+      - uses: actions/checkout@v2.4.0
+        with:
+          persist-credentials: false
+
+      - name: Inject slug/short variables
+        uses: rlespinasse/github-slug-action@v4
+
+      - name: Run all zebrad tests
+        run: |
+          docker pull ${{ env.GAR_BASE }}/${{ env.IMAGE_NAME }}:${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}
+          docker run -e ZEBRA_SKIP_IPV6_TESTS --name zebrad-tests -t ${{ env.GAR_BASE }}/${{ env.IMAGE_NAME }}:${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }} cargo test --locked --release --features enable-sentry --workspace
+
+  test-fake-activation-heights:
+    name: Test with fake activation heights
+    runs-on: ubuntu-latest
+    needs: build
+    if: ${{ github.event.inputs.regenerate-disks != 'true' }}
+    steps:
+      - uses: actions/checkout@v2.4.0
+        with:
+          persist-credentials: false
+
+      - name: Inject slug/short variables
+        uses: rlespinasse/github-slug-action@v4
+
+      - name: Run tests with fake activation heights
+        run: |
+          docker pull ${{ env.GAR_BASE }}/${{ env.IMAGE_NAME }}:${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}
+          docker run -e ZEBRA_SKIP_IPV6_TESTS --name zebrad-tests -t ${{ env.GAR_BASE }}/${{ env.IMAGE_NAME }}:${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }} cargo test --locked --release --package zebra-state --lib -- with_fake_activation_heights
+
+  test-large-sync:
+    name: Test large sync
+    runs-on: ubuntu-latest
+    needs: build
+    if: ${{ github.event.inputs.regenerate-disks != 'true' }}
+    steps:
+      - uses: actions/checkout@v2.4.0
+        with:
+          persist-credentials: false
+
+      - name: Inject slug/short variables
+        uses: rlespinasse/github-slug-action@v4
+
+      - name: Run zebrad large sync tests
+        run: |
+          docker pull ${{ env.GAR_BASE }}/${{ env.IMAGE_NAME }}:${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}
+          docker run -e ZEBRA_SKIP_IPV6_TESTS --name zebrad-tests -t ${{ env.GAR_BASE }}/${{ env.IMAGE_NAME }}:${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }} cargo test --locked --release --features enable-sentry --test acceptance sync_large_checkpoints_ -- --ignored
+
+  test-zunstable:
+    name: Test with Zunstable options
+    runs-on: ubuntu-latest
+    needs: build
+    if: ${{ github.event.inputs.regenerate-disks != 'true' }}
+    steps:
+      - uses: actions/checkout@v2.4.0
+        with:
+          persist-credentials: false
+
+      - name: Inject slug/short variables
+        uses: rlespinasse/github-slug-action@v4
+
+      - name: Run Zunstable-options tests
+        run: |
+          docker pull ${{ env.GAR_BASE }}/${{ env.IMAGE_NAME }}:${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}
+          docker run -e ZEBRA_SKIP_IPV6_TESTS --name zebrad-tests -t ${{ env.GAR_BASE }}/${{ env.IMAGE_NAME }}:${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }} cargo test --locked --release --features enable-sentry --workspace -- -Zunstable-options --include-ignored
 
-  test:
-    name: Run all tests
+  regenerate-stateful-disks:
+    name: Renerate state disks
     runs-on: ubuntu-latest
+    needs: build
     steps:
       - uses: actions/checkout@v2.4.0
         with:
           persist-credentials: false
+          fetch-depth: '2'
+
+      - name: Get specific changed files
+        id: changed-files-specific
+        uses: tj-actions/changed-files@v14.4
+        with:
+          files: |
+            /zebra-state/**/disk_format.rs
+            /zebra-state/**/finalized_state.rs
+            /zebra-state/**/constants.rs
 
       - name: Inject slug/short variables
         uses: rlespinasse/github-slug-action@v4
 
-      - name: Set up gcloud
-        uses: google-github-actions/setup-gcloud@v0.5.0
+      - name: Downcase network name for disks
+        run: |
+          echo LOWER_NET_NAME="${{ github.event.inputs.network || env.NETWORK }}" | awk '{print tolower($0)}' >> $GITHUB_ENV
+
+      # Setup gcloud CLI
+      - name: Authenticate to Google Cloud
+        id: auth
+        uses: google-github-actions/auth@v0.5.0
         with:
-          project_id: ${{ env.PROJECT_ID }}
-          service_account_key: ${{ secrets.GCLOUD_AUTH }}
+          credentials_json: ${{ secrets.GOOGLE_CREDENTIALS }}
+
+      - name: Create GCP compute instance
+        id: create-instance
+        if: ${{ steps.changed-files-specific.outputs.any_changed == 'true' }} || ${{ github.event.inputs.regenerate-disks == 'true' }}
+        run: |
+          gcloud compute instances create-with-container "zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}" \
+          --boot-disk-size 100GB \
+          --boot-disk-type pd-ssd \
+          --create-disk name="zebrad-cache-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}-${{ env.lower_net_name }}-canopy",size=100GB,type=pd-ssd \
+          --container-mount-disk mount-path='/zebrad-cache',name="zebrad-cache-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}-${{ env.lower_net_name }}-canopy" \
+          --container-image ${{ env.GAR_BASE }}/${{ env.IMAGE_NAME }}:${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }} \
+          --container-restart-policy=never \
+          --container-stdin \
+          --container-tty \
+          --container-command="cargo" \
+          --container-arg="test" \
+          --container-arg="--locked" \
+          --container-arg="--release" \
+          --container-arg="--features" \
+          --container-arg="enable-sentry,test_sync_to_mandatory_checkpoint_${{ env.lower_net_name }}" \
+          --container-arg="--manifest-path" \
+          --container-arg="zebrad/Cargo.toml" \
+          --container-arg="sync_to_mandatory_checkpoint_${{ env.lower_net_name }}" \
+          --container-env=ZEBRA_SKIP_IPV6_TESTS=1 \
+          --machine-type ${{ env.MACHINE_TYPE }} \
+          --scopes cloud-platform \
+          --metadata=google-monitoring-enabled=true,google-logging-enabled=true \
+          --tags zebrad \
+          --zone "${{ env.ZONE }}"
+
+      # TODO: this approach is very mesy, but getting the just created container name is very error prone and GCP doesn't have a workaround for this without requiring a TTY
+      # This TODO relates to the following issues:
+      # https://github.com/actions/runner/issues/241
+      # https://www.googlecloudcommunity.com/gc/Infrastructure-Compute-Storage/SSH-into-Compute-Container-not-easily-possible/td-p/170915
+      - name: Get container name from logs
+        id: get-container-name
+        if: steps.create-instance.outcome == 'success'
+        run: |
+          INSTANCE_ID=$(gcloud compute instances describe zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }} --zone ${{ env.ZONE }} --format='value(id)')
+          echo "Using instance: $INSTANCE_ID"
+          while [[ ${CONTAINER_NAME} != *"zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}"* ]]; do
+              CONTAINER_NAME=$(gcloud logging read 'log_name=projects/${{ env.PROJECT_ID }}/logs/cos_system AND jsonPayload.MESSAGE:zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}' --format='value(jsonPayload.MESSAGE)' --limit=1 | grep -o '...-zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}-....' | tr -d "'.")
+              echo "Using container: ${CONTAINER_NAME} from instance: ${INSTANCE_ID}"
+              sleep 10
+          done
+          CONTAINER_NAME=$(gcloud logging read 'log_name=projects/${{ env.PROJECT_ID }}/logs/cos_system AND jsonPayload.MESSAGE:zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}' --format='value(jsonPayload.MESSAGE)' --limit=1 | grep -o '...-zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}-....' | tr -d "'.")
+          echo "::set-output name=zebra_container::$CONTAINER_NAME"
+
+      - name: Regenerate stateful disks logs
+        id: sync-to-checkpoint
+        run: |
+          gcloud compute ssh \
+          zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }} \
+          --zone ${{ env.ZONE }} \
+          --quiet \
+          --ssh-flag="-o ServerAliveInterval=5" \
+          --command="docker logs --follow ${{ env.ZEBRA_CONTAINER }}"
+        env:
+          ZEBRA_CONTAINER: ${{ steps.get-container-name.outputs.zebra_container }}
+
+      # Create image from disk that will be used to sync past mandatory checkpoint test
+      # Force the image creation as the disk is still attached even though is not being used by the container
+      - name: Create image from state disk
+        # Only run if the earlier step succeeds
+        if: steps.sync-to-checkpoint.outcome == 'success'
+        run: |
+          gcloud compute images create zebrad-cache-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}-${{ env.lower_net_name }}-canopy \
+          --force \
+          --source-disk=zebrad-cache-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}-${{ env.lower_net_name }}-canopy \
+          --source-disk-zone=${{ env.ZONE }} \
+          --storage-location=us \
+          --description="Created from head branch ${{ env.GITHUB_HEAD_REF_SLUG }} targeting ${{ env.GITHUB_BASE_REF_SLUG }} from PR ${{ env.GITHUB_REF_SLUG }} with commit ${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA }}"
+
+      - name: Write the disk SHORT_SHA to a txt
+        if: steps.sync-to-checkpoint.outcome == 'success'
+        run: |
+          short_sha=$(echo "${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}")
+          echo "$short_sha" > latest-disk-state-sha.txt
+
+      - name: Upload the disk state txt
+        uses: actions/upload-artifact@v2.3.1
+        with:
+          name: latest-disk-state-sha
+          path: latest-disk-state-sha.txt
+          retention-days: 1095
+
+      - name: Delete test instance
+        # Do not delete the instance if the sync timeouts in GitHub
+        if: ${{ steps.sync-to-checkpoint.outcome == 'success' }} || ${{ steps.sync-to-checkpoint.outcome == 'failure' }}
+        continue-on-error: true
+        run: |
+          gcloud compute instances delete "zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}" --delete-disks all --zone "${{ env.ZONE }}"
+
+  test-stateful-sync:
+    name: Test blocks sync
+    runs-on: ubuntu-latest
+    needs: [ build, regenerate-stateful-disks]
+    if: ${{ github.event.inputs.regenerate-disks != 'true' }}
+    steps:
+      - uses: actions/checkout@v2.4.0
+        with:
+          persist-credentials: false
+
+      - name: Inject slug/short variables
+        uses: rlespinasse/github-slug-action@v4
+
+      - name: Downcase network name for disks
+        run: |
+          echo LOWER_NET_NAME="${{ github.event.inputs.network || env.NETWORK }}" | awk '{print tolower($0)}' >> $GITHUB_ENV
+
+      # Get the latest uploaded txt with the disk SHORT_SHA from this workflow
+      - name: Download latest disk state SHORT_SHA
+        uses: dawidd6/action-download-artifact@v2.17.0
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          workflow: test.yml
+          name: latest-disk-state-sha
+          check_artifacts:  true
+
+      - name: Get disk state SHA from txt
+        id: get-disk-sha
+        run: |
+          output=$(cat latest-disk-state-sha.txt)
+          echo "::set-output name=sha::$output"
+
+      # Setup gcloud CLI
+      - name: Authenticate to Google Cloud
+        id: auth
+        uses: google-github-actions/auth@v0.5.0
+        with:
+          credentials_json: ${{ secrets.GOOGLE_CREDENTIALS }}
 
       # Creates Compute Engine virtual machine instance w/ disks
-      - name: Create instance
+      - name: Create GCP compute instance
+        id: create-instance
         run: |
-          gcloud compute instances create-with-container "zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_SHA_SHORT }}" \
+          gcloud compute instances create-with-container "zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}" \
           --boot-disk-size 100GB \
           --boot-disk-type pd-ssd \
-          --container-image rust:buster \
-          --container-mount-disk mount-path='/mainnet',name="zebrad-cache-${{ env.GITHUB_SHA_SHORT }}-mainnet-canopy" \
-          --container-restart-policy never \
-          --create-disk name="zebrad-cache-${{ env.GITHUB_SHA_SHORT }}-mainnet-canopy",image=zebrad-cache-1558f3378-mainnet-canopy \
+          --disk=boot=no,mode=rw,name=zebrad-cache-${{ env.DISK_SHORT_SHA }}-${{ env.lower_net_name }}-canopy \
+          --container-mount-disk=mount-path='/zebrad-cache',name=zebrad-cache-${{ env.DISK_SHORT_SHA }}-${{ env.lower_net_name }}-canopy \
+          --container-image ${{ env.GAR_BASE }}/${{ env.IMAGE_NAME }}:${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }} \
+          --container-restart-policy=never \
+          --container-stdin \
+          --container-tty \
+          --container-command="cargo" \
+          --container-arg="test" \
+          --container-arg="--locked" \
+          --container-arg="--release" \
+          --container-arg="--features" \
+          --container-arg="enable-sentry,test_sync_past_mandatory_checkpoint_${{ env.lower_net_name }}" \
+          --container-arg="--manifest-path" \
+          --container-arg="zebrad/Cargo.toml" \
+          --container-arg="sync_past_mandatory_checkpoint_${{ env.lower_net_name }}" \
+          --container-env=ZEBRA_SKIP_IPV6_TESTS=1 \
           --machine-type ${{ env.MACHINE_TYPE }} \
-          --service-account ${{ env.DEPLOY_SA }} \
           --scopes cloud-platform \
+          --metadata=google-monitoring-enabled=true,google-logging-enabled=true \
           --tags zebrad \
           --zone "${{ env.ZONE }}"
+        env:
+          DISK_SHORT_SHA: ${{ steps.get-disk-sha.outputs.sha }}
+
+      # TODO: this approach is very mesy, but getting the just created container name is very error prone and GCP doesn't have a workaround for this without requiring a TTY
+      # This TODO relates to the following issues:
+      # https://github.com/actions/runner/issues/241
+      # https://www.googlecloudcommunity.com/gc/Infrastructure-Compute-Storage/SSH-into-Compute-Container-not-easily-possible/td-p/170915
+      - name: Get container name from logs
+        id: get-container-name
+        if: steps.create-instance.outcome == 'success'
+        run: |
+          INSTANCE_ID=$(gcloud compute instances describe zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }} --zone ${{ env.ZONE }} --format='value(id)')
+          echo "Using instance: $INSTANCE_ID"
+          while [[ ${CONTAINER_NAME} != *"zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}"* ]]; do
+              CONTAINER_NAME=$(gcloud logging read 'log_name=projects/${{ env.PROJECT_ID }}/logs/cos_system AND jsonPayload.MESSAGE:zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}' --format='value(jsonPayload.MESSAGE)' --limit=1 | grep -o '...-zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}-....' | tr -d "'.")
+              echo "Using container: ${CONTAINER_NAME} from instance: ${INSTANCE_ID}"
+              sleep 10
+          done
+          CONTAINER_NAME=$(gcloud logging read 'log_name=projects/${{ env.PROJECT_ID }}/logs/cos_system AND jsonPayload.MESSAGE:zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}' --format='value(jsonPayload.MESSAGE)' --limit=1 | grep -o '...-zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}-....' | tr -d "'.")
+          echo "::set-output name=zebra_container::$CONTAINER_NAME"
+
+      - name: Sync past mandatory checkpoint logs
+        id: sync-past-checkpoint
+        run: |
+          gcloud compute ssh \
+          zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }} \
+          --zone ${{ env.ZONE }} \
+          --quiet \
+          --ssh-flag="-o ServerAliveInterval=5" \
+          --command="docker logs --follow ${{ env.ZEBRA_CONTAINER }}"
+        env:
+          ZEBRA_CONTAINER: ${{ steps.get-container-name.outputs.zebra_container }}
 
-      # Build and run test container
-      - name: Run all tests
-        run: |
-          gcloud compute ssh "zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_SHA_SHORT }}" --ssh-flag="-o ServerAliveInterval=5" --zone "${{ env.ZONE }}" --command \
-          "git clone -b ${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }} https://github.com/ZcashFoundation/zebra.git &&
-          cd zebra/ &&
-          docker build --build-arg SHORT_SHA=${{ env.GITHUB_SHA_SHORT }} -f docker/Dockerfile.test -t zebrad-test . &&
-          docker run -t -e ZEBRA_SKIP_IPV6_TESTS=1 zebrad-test:latest cargo test --workspace --no-fail-fast -- -Zunstable-options --include-ignored &&
-          docker run -t -e ZEBRA_SKIP_IPV6_TESTS=1 --mount type=bind,source=/mnt/disks/gce-containers-mounts/gce-persistent-disks/zebrad-cache-${{ env.GITHUB_SHA_SHORT }}-mainnet-canopy,target=/zebrad-cache zebrad-test:latest cargo test --verbose --features test_sync_past_mandatory_checkpoint_mainnet --manifest-path zebrad/Cargo.toml sync_past_mandatory_checkpoint_mainnet
-          "
-      # Clean up
       - name: Delete test instance
-        # Always run even if the earlier step fails
-        if: ${{ always() }}
+        # Do not delete the instance if the sync timeouts in GitHub
+        if: ${{ steps.sync-past-checkpoint.outcome == 'success' }} || ${{ steps.sync-past-checkpoint.outcome == 'failure' }}
+        continue-on-error: true
         run: |
-          gcloud compute instances delete "zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_SHA_SHORT }}" --delete-disks all --zone "${{ env.ZONE }}"
+          gcloud compute instances delete "zebrad-tests-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_EVENT_PULL_REQUEST_HEAD_SHA_SHORT || env.GITHUB_SHA_SHORT }}" --delete-disks all --zone "${{ env.ZONE }}"
diff --git a/.github/workflows/zcashd-manual-deploy.yml b/.github/workflows/zcashd-manual-deploy.yml
index 927ac5e6d67..846a43bd436 100644
--- a/.github/workflows/zcashd-manual-deploy.yml
+++ b/.github/workflows/zcashd-manual-deploy.yml
@@ -4,22 +4,22 @@ on:
   workflow_dispatch:
     inputs:
       network:
-        default: 'testnet'
+        default: 'Testnet'
       size:
         default: 10
 
 env:
   PROJECT_ID: ${{ secrets.GCP_PROJECT_ID }}
   REGION: us-central1
-  MACHINE_TYPE: n2-standard-4
-  DEPLOY_SA: cos-vm@${{ secrets.GCP_PROJECT_ID }}.iam.gserviceaccount.com
+  ZONE: us-central1-a
+  MACHINE_TYPE: c2-standard-4
 
 jobs:
-
   deploy:
     name: Deploy zcashd nodes
     runs-on: ubuntu-latest
     timeout-minutes: 30
+
     steps:
       - uses: actions/checkout@v2.4.0
         with:
@@ -38,14 +38,17 @@ jobs:
       # Create instance template from container image
       - name: Create instance template
         run: |
-          gcloud compute instance-templates create-with-container "zcashd-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_SHA_SHORT }}" \
-          --boot-disk-size 100GB \
-          --container-image "electriccoinco/zcashd" \
+          gcloud compute instance-templates create-with-container zcashd-${{ env.GITHUB_HEAD_REF_SLUG || env.GITHUB_REF_SLUG }}-${{ env.GITHUB_SHA_SHORT }} \
+          --boot-disk-size 10GB \
+          --boot-disk-type=pd-ssd \
+          --container-stdin \
+          --container-tty \
+          --container-image electriccoinco/zcashd \
           --container-env ZCASHD_NETWORK="${{ github.event.inputs.network }}" \
           --machine-type ${{ env.MACHINE_TYPE }} \
           --service-account ${{ env.DEPLOY_SA }} \
           --scopes cloud-platform \
-          --tags zcashd \
+          --tags zcashd
 
       # Check if our destination instance group exists already
       - name: Check if instance group exists
diff --git a/zebra-chain/src/transparent/serialize.rs b/zebra-chain/src/transparent/serialize.rs
index 0a9d01915c4..11cd98964e1 100644
--- a/zebra-chain/src/transparent/serialize.rs
+++ b/zebra-chain/src/transparent/serialize.rs
@@ -1,3 +1,5 @@
+//! Serializes and deserializes transparent data.
+
 use std::io;
 
 use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
@@ -14,13 +16,24 @@ use crate::{
 use super::{CoinbaseData, Input, OutPoint, Output, Script};
 
 /// The maximum length of the coinbase data.
+///
 /// Includes the encoded coinbase height, if any.
 ///
 /// > The number of bytes in the coinbase script, up to a maximum of 100 bytes.
 ///
-/// https://developer.bitcoin.org/reference/transactions.html#coinbase-input-the-input-of-the-first-transaction-in-a-block
+/// <https://developer.bitcoin.org/reference/transactions.html#coinbase-input-the-input-of-the-first-transaction-in-a-block>
 pub const MAX_COINBASE_DATA_LEN: usize = 100;
 
+/// The minimum length of the coinbase data.
+///
+/// Includes the encoded coinbase height, if any.
+///
+// TODO: Update the link below once the constant is documented in the
+// protocol.
+///
+/// <https://github.com/zcash/zips/issues/589>
+pub const MIN_COINBASE_DATA_LEN: usize = 2;
+
 /// The coinbase data for a genesis block.
 ///
 /// Zcash uses the same coinbase data for the Mainnet, Testnet, and Regtest
@@ -68,18 +81,19 @@ impl ZcashDeserialize for OutPoint {
 ///
 /// # Consensus
 ///
-/// > A coinbase transaction for a block at block height greater than 0 MUST have
-/// > a script that, as its first item, encodes the block height height as follows.
-/// > For height in the range {1..16}, the encoding is a single byte of value
-/// > 0x50 height. Otherwise, let heightBytes be the signed little-endian
-/// > representation of height, using the minimum nonzero number of bytes such that
-/// > the most significant byte is < 0x80.
-/// > The length of heightBytes MUST be in the range {1..5}.
-/// > Then the encoding is the length of heightBytes encoded as one byte,
-/// > followed by heightBytes itself. This matches the encoding used by Bitcoin in the
+/// > A coinbase transaction for a *block* at *block height* greater than 0 MUST have
+/// > a script that, as its first item, encodes the *block height* `height` as follows.
+/// > For `height` in the range {1..16}, the encoding is a single byte of value
+/// > `0x50` + `height`. Otherwise, let `heightBytes` be the signed little-endian
+/// > representation of `height`, using the minimum nonzero number of bytes such that
+/// > the most significant byte is < `0x80`.
+/// > The length of `heightBytes` MUST be in the range {1..5}.
+/// > Then the encoding is the length of `heightBytes` encoded as one byte,
+/// > followed by `heightBytes` itself. This matches the encoding used by Bitcoin in the
 /// > implementation of [BIP-34] (but the description here is to be considered normative).
 ///
 /// <https://zips.z.cash/protocol/protocol.pdf#txnconsensus>
+/// <https://github.com/bitcoin/bips/blob/master/bip-0034.mediawiki>
 pub(crate) fn parse_coinbase_height(
     mut data: Vec<u8>,
 ) -> Result<(block::Height, CoinbaseData), SerializationError> {
@@ -262,9 +276,14 @@ impl ZcashDeserialize for Input {
             }
 
             let data: Vec<u8> = (&mut reader).zcash_deserialize_into()?;
+
+            // Check the coinbase data length.
             if data.len() > MAX_COINBASE_DATA_LEN {
-                return Err(SerializationError::Parse("coinbase has too much data"));
+                return Err(SerializationError::Parse("coinbase data is too long"));
+            } else if data.len() < MIN_COINBASE_DATA_LEN {
+                return Err(SerializationError::Parse("coinbase data is too short"));
             }
+
             let (height, data) = parse_coinbase_height(data)?;
 
             let sequence = reader.read_u32::<LittleEndian>()?;
diff --git a/zebra-network/src/peer/handshake.rs b/zebra-network/src/peer/handshake.rs
index d5d5b4d1b32..cc784a46730 100644
--- a/zebra-network/src/peer/handshake.rs
+++ b/zebra-network/src/peer/handshake.rs
@@ -588,13 +588,29 @@ where
     debug!(?our_version, "sending initial version message");
     peer_conn.send(our_version).await?;
 
-    let remote_msg = peer_conn
+    let mut remote_msg = peer_conn
         .next()
         .await
         .ok_or(HandshakeError::ConnectionClosed)??;
 
-    // Check that we got a Version and destructure its fields into the local scope.
-    debug!(?remote_msg, "got message from remote peer");
+    // Wait for next message if the one we got is not Version
+    loop {
+        match remote_msg {
+            Message::Version { .. } => {
+                debug!(?remote_msg, "got version message from remote peer");
+                break;
+            }
+            _ => {
+                remote_msg = peer_conn
+                    .next()
+                    .await
+                    .ok_or(HandshakeError::ConnectionClosed)??;
+                debug!(?remote_msg, "ignoring non-version message from remote peer");
+            }
+        }
+    }
+
+    // If we got a Version message, destructure its fields into the local scope.
     let (remote_nonce, remote_services, remote_version, remote_canonical_addr, user_agent) =
         if let Message::Version {
             version,
@@ -700,14 +716,26 @@ where
 
     peer_conn.send(Message::Verack).await?;
 
-    let remote_msg = peer_conn
+    let mut remote_msg = peer_conn
         .next()
         .await
         .ok_or(HandshakeError::ConnectionClosed)??;
-    if let Message::Verack = remote_msg {
-        debug!("got verack from remote peer");
-    } else {
-        Err(HandshakeError::UnexpectedMessage(Box::new(remote_msg)))?;
+
+    // Wait for next message if the one we got is not Verack
+    loop {
+        match remote_msg {
+            Message::Verack => {
+                debug!(?remote_msg, "got verack message from remote peer");
+                break;
+            }
+            _ => {
+                remote_msg = peer_conn
+                    .next()
+                    .await
+                    .ok_or(HandshakeError::ConnectionClosed)??;
+                debug!(?remote_msg, "ignoring non-verack message from remote peer");
+            }
+        }
     }
 
     Ok((remote_version, remote_services, remote_canonical_addr))