yaml
# .github/workflows/deploy.yml
name: CI/CD Pipeline

on:
  push:
    branches: [main, develop]
  pull_request:
    branches: [main]

jobs:
  # ====== STEP 1: TEST ======
  test:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        node-version: [18, 20]
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: ${{ matrix.node-version }}
          cache: 'npm'
      - run: npm ci
      - run: npm run lint
      - run: npm run type-check
      - run: npm test -- --coverage
      - uses: actions/upload-artifact@v4
        with:
          name: coverage-report
          path: coverage/

  # ====== STEP 2: BUILD DOCKER ======
  build:
    needs: test
    runs-on: ubuntu-latest
    if: github.ref == 'refs/heads/main'
    steps:
      - uses: actions/checkout@v4
      - uses: docker/setup-buildx-action@v3
      - uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
      - uses: docker/build-push-action@v5
        with:
          push: true
          tags: |
            ghcr.io/${{ github.repository }}:latest
            ghcr.io/${{ github.repository }}:${{ github.sha }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

  # ====== STEP 3: DEPLOY ======
  deploy:
    needs: build
    runs-on: ubuntu-latest
    environment: production
    steps:
      - name: Deploy to production
        run: |
          # SSH deploy, Kubernetes apply, or cloud CLI
          echo "Deploying ${{ github.sha }} to production"

yaml
  preview:
    if: github.event_name == 'pull_request'
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Deploy Preview
        id: deploy
        run: |
          PREVIEW_URL="https://pr-${{ github.event.number }}.preview.myapp.com"
          echo "url=$PREVIEW_URL" >> $GITHUB_OUTPUT
      - name: Comment PR
        uses: actions/github-script@v7
        with:
          script: |
            github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: '🚀 Preview: ${{ steps.deploy.outputs.url }}'
            })

yaml
  migrate:
    needs: build
    runs-on: ubuntu-latest
    steps:
      - name: Run migrations
        run: |
          npx prisma migrate deploy
        env:
          DATABASE_URL: ${{ secrets.DATABASE_URL }}

yaml
  rollback:
    needs: deploy
    if: failure()
    runs-on: ubuntu-latest
    steps:
      - name: Rollback to previous version
        run: |
          # Deploy previous stable image
          kubectl set image deployment/app \
            app=ghcr.io/${{ github.repository }}:${{ env.PREVIOUS_SHA }}