diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d89599fb..fb10adf3 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -6,32 +6,158 @@ on:
   pull_request:
     branches: [ main ]
 
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
 jobs:
-  test:
+  lint:
     runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Bun
+        uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - name: Cache bun dependencies
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.bun/install/cache
+            node_modules
+            web/node_modules
+          key: ${{ runner.os }}-bun-${{ hashFiles('**/bun.lock', '**/package.json') }}
+          restore-keys: |
+            ${{ runner.os }}-bun-
+
+      - name: Install dependencies
+        run: |
+          bun install
+          cd web && bun install
 
+      - name: Lint
+        run: bun run lint
+
+      - name: Format check
+        run: bun run format:check
+
+      - name: Typecheck
+        run: bun x tsc --noEmit
+
+  build:
+    runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+      - uses: actions/checkout@v4
+
+      - name: Set up Bun
+        uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - name: Cache bun dependencies
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.bun/install/cache
+            node_modules
+            web/node_modules
+          key: ${{ runner.os }}-bun-${{ hashFiles('**/bun.lock', '**/package.json') }}
+          restore-keys: |
+            ${{ runner.os }}-bun-
+
+      - name: Install dependencies
+        run: |
+          bun install
+          cd web && bun install
+
+      - name: Build
+        run: bun run build
+
+      - name: Upload build artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: dist
+          path: dist/
+          retention-days: 1
+
+  test:
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          name: dist
+          path: dist/
+
+      - name: Set up Bun
+        uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - name: Cache bun dependencies
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.bun/install/cache
+            node_modules
+            web/node_modules
+          key: ${{ runner.os }}-bun-${{ hashFiles('**/bun.lock', '**/package.json') }}
+          restore-keys: |
+            ${{ runner.os }}-bun-
+
+      - name: Install dependencies
+        run: |
+          bun install
+          cd web && bun install
 
-    - name: Set up Node.js
-      uses: actions/setup-node@v4
-      with:
-        node-version: '22'
-        cache: 'npm'
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
 
-    - name: Set up Bun
-      uses: oven-sh/setup-bun@v2
+      - name: Log in to Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
 
-    - name: Install dependencies
-      run: |
-        bun install
-        cd web && bun install
+      - name: Check for Dockerfile changes
+        id: docker-changes
+        run: |
+          # For PRs, compare against base branch
+          # For pushes, compare against previous commit
+          if [ "${{ github.event_name }}" = "pull_request" ]; then
+            BASE_SHA="${{ github.event.pull_request.base.sha }}"
+          else
+            BASE_SHA="${{ github.event.before }}"
+          fi
 
-    - name: Typecheck
-      run: bun x tsc --noEmit
+          # Check if any files in perry/ directory changed
+          if git diff --name-only "$BASE_SHA" HEAD 2>/dev/null | grep -q "^perry/"; then
+            echo "Dockerfile or related files changed - will rebuild and update cache"
+            echo "changed=true" >> $GITHUB_OUTPUT
+          else
+            echo "No Dockerfile changes detected - using cached layers"
+            echo "changed=false" >> $GITHUB_OUTPUT
+          fi
 
-    - name: Build
-      run: bun run build
+      - name: Build workspace image (with cache)
+        uses: docker/build-push-action@v6
+        with:
+          context: ./perry
+          load: true
+          tags: workspace:latest
+          cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:buildcache-test
+          cache-to: ${{ steps.docker-changes.outputs.changed == 'true' && format('type=registry,ref={0}/{1}:buildcache-test,mode=max', env.REGISTRY, env.IMAGE_NAME) || '' }}
 
-    - name: Run tests
-      run: bun run test
+      - name: Run tests
+        run: |
+          # Skip Docker build in test setup since we already have the image
+          export SKIP_DOCKER_BUILD=true
+          bun run test
diff --git a/test/setup/global.js b/test/setup/global.js
index 6ab161dc..48a0491b 100644
--- a/test/setup/global.js
+++ b/test/setup/global.js
@@ -27,7 +27,26 @@ async function cleanupOrphanedResources() {
   } catch {}
 }
 
+function imageExists() {
+  try {
+    execSync('docker image inspect workspace:latest', { stdio: 'ignore' });
+    return true;
+  } catch {
+    return false;
+  }
+}
+
 async function buildImage() {
+  if (process.env.SKIP_DOCKER_BUILD === 'true' && imageExists()) {
+    console.log('\n✅ Using existing workspace:latest image (SKIP_DOCKER_BUILD=true)\n');
+    return;
+  }
+
+  if (imageExists() && !process.env.FORCE_DOCKER_BUILD) {
+    console.log('\n✅ Using existing workspace:latest image\n');
+    return;
+  }
+
   return new Promise((resolve, reject) => {
     console.log('\n🏗️  Building workspace Docker image once for all tests...\n');