diff --git a/.github/actions/docker-build-ecr/action.yml b/.github/actions/docker-build-ecr/action.yml
new file mode 100644
index 00000000000..34854c5e6c6
--- /dev/null
+++ b/.github/actions/docker-build-ecr/action.yml
@@ -0,0 +1,101 @@
+name: Docker build and push to ECR (with ECR registry cache)
+description: |
+  Build a Docker image and push to AWS ECR, using an ECR-stored layer cache
+  rather than the GHA cache backend. This is a temporary inline replacement
+  for `cardstack/gh-actions/.github/workflows/docker-ecr.yml` while we
+  iterate on which cache backend works best for boxel's large pnpm-fetch
+  layers (the GHA backend transfers them too slowly to be a net win).
+
+  Cache lives at `<ecr-repo>:buildcache` in the same ECR repository as the
+  image tags. ECR pulls inside the same AWS region are typically much faster
+  than the GHA cache service.
+
+inputs:
+  repository:
+    required: true
+    description: ECR repository name (without registry prefix)
+  environment:
+    required: true
+    description: Deployment environment (staging or production)
+  dockerfile:
+    required: false
+    default: "Dockerfile"
+    description: Path to the Dockerfile
+  context:
+    required: false
+    default: "."
+    description: Docker build context
+  build-args:
+    required: false
+    default: ""
+    description: Build args passed to docker/build-push-action
+  platforms:
+    required: false
+    default: "linux/amd64"
+    description: Target platform
+
+outputs:
+  image:
+    description: Final image tag (sha-tagged) suitable for ECS task-def update
+    value: ${{ steps.tags.outputs.tag_sha }}
+
+runs:
+  using: composite
+  steps:
+    - uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
+
+    - name: Set up AWS role for environment
+      shell: bash
+      env:
+        INPUT_ENVIRONMENT: ${{ inputs.environment }}
+      run: |
+        if [ "$INPUT_ENVIRONMENT" = "production" ]; then
+          echo "AWS_ROLE_ARN=arn:aws:iam::120317779495:role/github" >> "$GITHUB_ENV"
+        elif [ "$INPUT_ENVIRONMENT" = "staging" ]; then
+          echo "AWS_ROLE_ARN=arn:aws:iam::680542703984:role/github" >> "$GITHUB_ENV"
+        else
+          echo "unrecognized environment: $INPUT_ENVIRONMENT"
+          exit 1
+        fi
+
+    - name: Configure AWS credentials
+      uses: aws-actions/configure-aws-credentials@d979d5b3a71173a29b74b5b88418bfda9437d885 # v6.1.1
+      with:
+        role-to-assume: ${{ env.AWS_ROLE_ARN }}
+        aws-region: us-east-1
+
+    - id: login-ecr
+      uses: aws-actions/amazon-ecr-login@fa648b43de3d4d023bcb3f89ed6940096949c419 # v2.1.5
+
+    - id: tags
+      shell: bash
+      env:
+        REGISTRY: ${{ steps.login-ecr.outputs.registry }}
+        REPOSITORY: ${{ inputs.repository }}
+        ENVIRONMENT: ${{ inputs.environment }}
+      run: |
+        TAG_PREFIX="$REGISTRY/$REPOSITORY"
+        {
+          echo "tag_sha=${TAG_PREFIX}:${GITHUB_SHA::7}"
+          echo "tag_env=${TAG_PREFIX}:${ENVIRONMENT}"
+          echo "tag_latest=${TAG_PREFIX}:latest"
+          echo "tag_buildcache=${TAG_PREFIX}:buildcache"
+        } >> "$GITHUB_OUTPUT"
+
+    - name: Build and push
+      uses: docker/build-push-action@bcafcacb16a39f128d818304e6c9c0c18556b85f # v7.1.0
+      with:
+        context: ${{ inputs.context }}
+        file: ${{ inputs.dockerfile }}
+        push: true
+        # `image-manifest=true,oci-mediatypes=true` is required for the
+        # registry cache to round-trip through ECR — ECR rejects the
+        # default cache manifest format buildx uses for other registries.
+        cache-from: type=registry,ref=${{ steps.tags.outputs.tag_buildcache }}
+        cache-to: type=registry,ref=${{ steps.tags.outputs.tag_buildcache }},mode=max,image-manifest=true,oci-mediatypes=true
+        platforms: ${{ inputs.platforms }}
+        build-args: ${{ inputs.build-args }}
+        tags: |
+          ${{ steps.tags.outputs.tag_latest }}
+          ${{ steps.tags.outputs.tag_sha }}
+          ${{ steps.tags.outputs.tag_env }}
diff --git a/.github/workflows/manual-deploy.yml b/.github/workflows/manual-deploy.yml
index 09daa9d672a..764ba6f2136 100644
--- a/.github/workflows/manual-deploy.yml
+++ b/.github/workflows/manual-deploy.yml
@@ -73,14 +73,29 @@ jobs:
               description: 'Deployment started',
             });
 
+  # Temporarily inlined (CS-11143): the reusable docker-ecr workflow in
+  # cardstack/gh-actions caches via `type=gha`, which is a net loss for our
+  # large pnpm-fetch layers — observed cache transfer ~230s vs ~30s to just
+  # rerun the fetch. We call a local composite action instead that uses an
+  # ECR registry cache (same AWS region as the build runner, much faster).
+  # Once we're confident in the approach we can fold it back into the shared
+  # action.
   build-ai-bot:
     name: Build ai-bot Docker image
-    uses: cardstack/gh-actions/.github/workflows/docker-ecr.yml@main
-    secrets: inherit
-    with:
-      repository: "boxel-ai-bot-${{ inputs.environment }}"
-      environment: ${{ inputs.environment }}
-      dockerfile: "packages/ai-bot/Dockerfile"
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write
+    outputs:
+      image: ${{ steps.build.outputs.image }}
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      - id: build
+        uses: ./.github/actions/docker-build-ecr
+        with:
+          repository: "boxel-ai-bot-${{ inputs.environment }}"
+          environment: ${{ inputs.environment }}
+          dockerfile: "packages/ai-bot/Dockerfile"
 
   deploy-ai-bot:
     needs: [build-ai-bot, post-migrate-db]
@@ -97,12 +112,20 @@ jobs:
 
   build-bot-runner:
     name: Build bot-runner Docker image
-    uses: cardstack/gh-actions/.github/workflows/docker-ecr.yml@main
-    secrets: inherit
-    with:
-      repository: "boxel-bot-runner-${{ inputs.environment }}"
-      environment: ${{ inputs.environment }}
-      dockerfile: "packages/bot-runner/Dockerfile"
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write
+    outputs:
+      image: ${{ steps.build.outputs.image }}
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      - id: build
+        uses: ./.github/actions/docker-build-ecr
+        with:
+          repository: "boxel-bot-runner-${{ inputs.environment }}"
+          environment: ${{ inputs.environment }}
+          dockerfile: "packages/bot-runner/Dockerfile"
 
   deploy-bot-runner:
     needs: [build-bot-runner, post-migrate-db]
@@ -142,56 +165,96 @@ jobs:
 
   build-realm-server:
     name: Build realm-server Docker image
-    uses: cardstack/gh-actions/.github/workflows/docker-ecr.yml@main
-    secrets: inherit
-    with:
-      repository: "boxel-realm-server-${{ inputs.environment }}"
-      environment: ${{ inputs.environment }}
-      dockerfile: "packages/realm-server/realm-server.Dockerfile"
-      build-args: |
-        "realm_server_script=start:${{ inputs.environment }}"
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write
+    outputs:
+      image: ${{ steps.build.outputs.image }}
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      - id: build
+        uses: ./.github/actions/docker-build-ecr
+        with:
+          repository: "boxel-realm-server-${{ inputs.environment }}"
+          environment: ${{ inputs.environment }}
+          dockerfile: "packages/realm-server/realm-server.Dockerfile"
+          build-args: |
+            "realm_server_script=start:${{ inputs.environment }}"
 
   build-prerender-manager:
     name: Build prerender manager Docker image
-    uses: cardstack/gh-actions/.github/workflows/docker-ecr.yml@main
-    secrets: inherit
-    with:
-      repository: "boxel-prerender-manager-${{ inputs.environment }}"
-      environment: ${{ inputs.environment }}
-      dockerfile: "packages/realm-server/prerender-manager.Dockerfile"
-      build-args: |
-        "prerender_manager_script=start:prerender-manager"
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write
+    outputs:
+      image: ${{ steps.build.outputs.image }}
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      - id: build
+        uses: ./.github/actions/docker-build-ecr
+        with:
+          repository: "boxel-prerender-manager-${{ inputs.environment }}"
+          environment: ${{ inputs.environment }}
+          dockerfile: "packages/realm-server/prerender-manager.Dockerfile"
+          build-args: |
+            "prerender_manager_script=start:prerender-manager"
 
   build-prerender:
     name: Build prerender Docker image
-    uses: cardstack/gh-actions/.github/workflows/docker-ecr.yml@main
-    secrets: inherit
-    with:
-      repository: "boxel-prerender-server-${{ inputs.environment }}"
-      environment: ${{ inputs.environment }}
-      dockerfile: "packages/realm-server/prerender.Dockerfile"
-      build-args: |
-        "prerender_script=start:prerender-${{ inputs.environment }}"
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write
+    outputs:
+      image: ${{ steps.build.outputs.image }}
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      - id: build
+        uses: ./.github/actions/docker-build-ecr
+        with:
+          repository: "boxel-prerender-server-${{ inputs.environment }}"
+          environment: ${{ inputs.environment }}
+          dockerfile: "packages/realm-server/prerender.Dockerfile"
+          build-args: |
+            "prerender_script=start:prerender-${{ inputs.environment }}"
 
   build-worker:
     name: Build worker Docker image
-    uses: cardstack/gh-actions/.github/workflows/docker-ecr.yml@main
-    secrets: inherit
-    with:
-      repository: "boxel-worker-${{ inputs.environment }}"
-      environment: ${{ inputs.environment }}
-      dockerfile: "packages/realm-server/worker.Dockerfile"
-      build-args: |
-        "worker_script=start:worker-${{ inputs.environment }}"
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write
+    outputs:
+      image: ${{ steps.build.outputs.image }}
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      - id: build
+        uses: ./.github/actions/docker-build-ecr
+        with:
+          repository: "boxel-worker-${{ inputs.environment }}"
+          environment: ${{ inputs.environment }}
+          dockerfile: "packages/realm-server/worker.Dockerfile"
+          build-args: |
+            "worker_script=start:worker-${{ inputs.environment }}"
 
   build-pg-migration:
     name: Build pg-migration Docker image
-    uses: cardstack/gh-actions/.github/workflows/docker-ecr.yml@main
-    secrets: inherit
-    with:
-      repository: "boxel-pg-migration-${{ inputs.environment }}"
-      environment: ${{ inputs.environment }}
-      dockerfile: "packages/postgres/Dockerfile"
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write
+    outputs:
+      image: ${{ steps.build.outputs.image }}
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      - id: build
+        uses: ./.github/actions/docker-build-ecr
+        with:
+          repository: "boxel-pg-migration-${{ inputs.environment }}"
+          environment: ${{ inputs.environment }}
+          dockerfile: "packages/postgres/Dockerfile"
 
   migrate-db:
     # use "deploy-host" and "build-realm-server" as deps so we can run
diff --git a/packages/postgres/Dockerfile b/packages/postgres/Dockerfile
index 4387e42ed42..887a4381d62 100644
--- a/packages/postgres/Dockerfile
+++ b/packages/postgres/Dockerfile
@@ -6,8 +6,17 @@ ARG PNPM_VERSION
 RUN apt-get update && apt-get install -y postgresql
 RUN npm install -g pnpm@${PNPM_VERSION}
 WORKDIR /boxel
+
+# Cache-friendly dependency fetch: this layer only re-runs when the lockfile
+# (or patches it references) changes, not on every source edit. `pnpm fetch`
+# populates the global pnpm store in $HOME from the lockfile alone, so the
+# subsequent `pnpm install --offline` doesn't need the registry.
+COPY pnpm-lock.yaml pnpm-workspace.yaml ./
+COPY patches/ ./patches
+RUN CI=1 pnpm fetch
+
 COPY . .
-RUN pnpm install --frozen-lockfile
+RUN CI=1 pnpm install -r --offline
 
 WORKDIR /boxel/packages/postgres
 
diff --git a/packages/realm-server/prerender-manager.Dockerfile b/packages/realm-server/prerender-manager.Dockerfile
index c168bbdd568..87c59b2bc95 100644
--- a/packages/realm-server/prerender-manager.Dockerfile
+++ b/packages/realm-server/prerender-manager.Dockerfile
@@ -9,14 +9,15 @@ WORKDIR /realm-server
 RUN apt-get update && apt-get install -y ca-certificates curl unzip jq
 RUN npm install -g pnpm@11.0.9
 
-COPY pnpm-lock.yaml ./
-
+# Cache-friendly dependency fetch: this layer only re-runs when the lockfile
+# (or patches it references) changes, not on every source edit. `pnpm fetch`
+# populates the global pnpm store in $HOME from the lockfile alone, so the
+# subsequent `pnpm install --offline` doesn't need the registry.
+COPY pnpm-lock.yaml pnpm-workspace.yaml ./
 COPY patches/ ./patches
-COPY vendor/ ./vendor
-
-ADD . ./
-
 RUN CI=1 pnpm fetch
+
+COPY . ./
 RUN CI=1 pnpm install -r --offline
 
 EXPOSE 4222
diff --git a/packages/realm-server/prerender.Dockerfile b/packages/realm-server/prerender.Dockerfile
index 9963e43b4e3..f1a24eac451 100644
--- a/packages/realm-server/prerender.Dockerfile
+++ b/packages/realm-server/prerender.Dockerfile
@@ -60,14 +60,15 @@ ENV PUPPETEER_CHROME_ARGS="--disable-dev-shm-usage"
 
 RUN mkdir -p /home/pptruser/Downloads "${PUPPETEER_CACHE_DIR}"
 
-COPY pnpm-lock.yaml ./
-
+# Cache-friendly dependency fetch: this layer only re-runs when the lockfile
+# (or patches it references) changes, not on every source edit. `pnpm fetch`
+# populates the global pnpm store in $HOME from the lockfile alone, so the
+# subsequent `pnpm install --offline` doesn't need the registry.
+COPY pnpm-lock.yaml pnpm-workspace.yaml ./
 COPY patches/ ./patches
-COPY vendor/ ./vendor
-
-ADD . ./
-
 RUN CI=1 pnpm fetch
+
+COPY . ./
 RUN CI=1 pnpm install -r --offline
 RUN chown -R pptruser:pptruser /home/pptruser /realm-server
 
diff --git a/packages/realm-server/realm-server.Dockerfile b/packages/realm-server/realm-server.Dockerfile
index 1d4f3cf0715..4f236466384 100644
--- a/packages/realm-server/realm-server.Dockerfile
+++ b/packages/realm-server/realm-server.Dockerfile
@@ -9,14 +9,15 @@ WORKDIR /realm-server
 RUN apt-get update && apt-get install -y ca-certificates curl unzip postgresql jq rsync git
 RUN npm install -g pnpm@11.0.9
 
-COPY pnpm-lock.yaml ./
-
+# Cache-friendly dependency fetch: this layer only re-runs when the lockfile
+# (or patches it references) changes, not on every source edit. `pnpm fetch`
+# populates the global pnpm store in $HOME from the lockfile alone, so the
+# subsequent `pnpm install --offline` doesn't need the registry.
+COPY pnpm-lock.yaml pnpm-workspace.yaml ./
 COPY patches/ ./patches
-COPY vendor/ ./vendor
-
-ADD . ./
-
 RUN CI=1 pnpm fetch
+
+COPY . ./
 RUN CI=1 pnpm install -r --offline
 
 EXPOSE 3000
diff --git a/packages/realm-server/worker.Dockerfile b/packages/realm-server/worker.Dockerfile
index be8b5438423..fcca828d42c 100644
--- a/packages/realm-server/worker.Dockerfile
+++ b/packages/realm-server/worker.Dockerfile
@@ -9,14 +9,15 @@ WORKDIR /realm-server
 RUN apt-get update && apt-get install -y ca-certificates curl unzip postgresql jq
 RUN npm install -g pnpm@11.0.9
 
-COPY pnpm-lock.yaml ./
-
+# Cache-friendly dependency fetch: this layer only re-runs when the lockfile
+# (or patches it references) changes, not on every source edit. `pnpm fetch`
+# populates the global pnpm store in $HOME from the lockfile alone, so the
+# subsequent `pnpm install --offline` doesn't need the registry.
+COPY pnpm-lock.yaml pnpm-workspace.yaml ./
 COPY patches/ ./patches
-COPY vendor/ ./vendor
-
-ADD . ./
-
 RUN CI=1 pnpm fetch
+
+COPY . ./
 RUN CI=1 pnpm install -r --offline
 
 EXPOSE 3000