CI/CD and Automation
Overview
Automate quality gates so that no change reaches production without passing tests, lint, type checking, and build. CI/CD is the enforcement mechanism for every other skill — it catches what humans and agents miss, and it does so consistently on every single change.
Shift Left: Catch problems as early in the pipeline as possible. A bug caught in linting costs minutes; the same bug caught in production costs hours. Move checks upstream — static analysis before tests, tests before staging, staging before production.
Faster is Safer: Smaller batches and more frequent releases reduce risk, not increase it. A deployment with 3 changes is easier to debug than one with 30. Frequent releases build confidence in the release process itself.
When to Use
- Setting up a new project's CI pipeline
- Adding or modifying automated checks
- Configuring deployment pipelines
- When a change should trigger automated verification
- Debugging CI failures
The Quality Gate Pipeline
Every change goes through these gates before merge:
Pull Request Opened │ ▼ ┌─────────────────┐ │ LINT CHECK │ eslint, prettier │ ↓ pass │ │ TYPE CHECK │ tsc --noEmit │ ↓ pass │ │ UNIT TESTS │ jest/vitest │ ↓ pass │ │ BUILD │ npm run build │ ↓ pass │ │ INTEGRATION │ API/DB tests │ ↓ pass │ │ E2E (optional) │ Playwright/Cypress │ ↓ pass │ │ SECURITY AUDIT │ npm audit │ ↓ pass │ │ BUNDLE SIZE │ bundlesize check └─────────────────┘ │ ▼ Ready for review
No gate can be skipped. If lint fails, fix lint — don't disable the rule. If a test fails, fix the code — don't skip the test.
GitHub Actions Configuration
Basic CI Pipeline
yaml# .github/workflows/ci.yml name: CI on: pull_request: branches: [main] push: branches: [main] jobs: quality: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - uses: actions/setup-node@v4 with: node-version: '22' cache: 'npm' - name: Install dependencies run: npm ci - name: Lint run: npm run lint - name: Type check run: npx tsc --noEmit - name: Test run: npm test -- --coverage - name: Build run: npm run build - name: Security audit run: npm audit --audit-level=high
With Database Integration Tests
yamlintegration: runs-on: ubuntu-latest services: postgres: image: postgres:16 env: POSTGRES_DB: testdb POSTGRES_USER: ci_user POSTGRES_PASSWORD: ${{ secrets.CI_DB_PASSWORD }} ports: - 5432:5432 options: >- --health-cmd pg_isready --health-interval 10s --health-timeout 5s --health-retries 5 steps: - uses: actions/checkout@v4 - uses: actions/setup-node@v4 with: node-version: '22' cache: 'npm' - run: npm ci - name: Run migrations run: npx prisma migrate deploy env: DATABASE_URL: postgresql://ci_user:${{ secrets.CI_DB_PASSWORD }}@localhost:5432/testdb - name: Integration tests run: npm run test:integration env: DATABASE_URL: postgresql://ci_user:${{ secrets.CI_DB_PASSWORD }}@localhost:5432/testdb
Note: Even for CI-only test databases, use GitHub Secrets for credentials rather than hardcoding values. This builds good habits and prevents accidental reuse of test credentials in other contexts.
E2E Tests
yamle2e: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - uses: actions/setup-node@v4 with: node-version: '22' cache: 'npm' - run: npm ci - name: Install Playwright run: npx playwright install --with-deps chromium - name: Build run: npm run build - name: Run E2E tests run: npx playwright test - uses: actions/upload-artifact@v4 if: failure() with: name: playwright-report path: playwright-report/
Feeding CI Failures Back to Agents
The power of CI with AI agents is the feedback loop. When CI fails:
CI fails │ ▼ Copy the failure output │ ▼ Feed it to the agent: "The CI pipeline failed with this error: [paste specific error] Fix the issue and verify locally before pushing again." │ ▼ Agent fixes → pushes → CI runs again
Key patterns:
Lint failure → Agent runs `npm run lint --fix` and commits Type error → Agent reads the error location and fixes the type Test failure → Agent follows debugging-and-error-recovery skill Build error → Agent checks config and dependencies
Deployment Strategies
Preview Deployments
Every PR gets a preview deployment for manual testing:
yaml# Deploy preview on PR (Vercel/Netlify/etc.) deploy-preview: runs-on: ubuntu-latest if: github.event_name == 'pull_request' steps: - uses: actions/checkout@v4 - name: Deploy preview run: npx vercel --token=${{ secrets.VERCEL_TOKEN }}
Feature Flags
Feature flags decouple deployment from release. Deploy incomplete or risky features behind flags so you can:
- Ship code without enabling it. Merge to main early, enable when ready.
- Roll back without redeploying. Disable the flag instead of reverting code.
- Canary new features. Enable for 1% of users, then 10%, then 100%.
- Run A/B tests. Compare behavior with and without the feature.
typescript// Simple feature flag pattern if (featureFlags.isEnabled('new-checkout-flow', { userId })) { return renderNewCheckout(); } return renderLegacyCheckout();
Flag lifecycle: Create → Enable for testing → Canary → Full rollout → Remove the flag and dead code. Flags that live forever become technical debt — set a cleanup date when you create them.
Staged Rollouts
PR merged to main │ ▼ Staging deployment (auto) │ Manual verification ▼ Production deployment (manual trigger or auto after staging) │ ▼ Monitor for errors (15-minute window) │ ├── Errors detected → Rollback └── Clean → Done
Rollback Plan
Every deployment should be reversible:
yaml# Manual rollback workflow name: Rollback on: workflow_dispatch: inputs: version: description: 'Version to rollback to' required: true jobs: rollback: runs-on: ubuntu-latest steps: - name: Rollback deployment run: | # Deploy the specified previous version npx vercel rollback ${{ inputs.version }}
Environment Management
.env.example → Committed (template for developers) .env → NOT committed (local development) .env.test → Committed (test environment, no real secrets) CI secrets → Stored in GitHub Secrets / vault Production secrets → Stored in deployment platform / vault
CI should never have production secrets. Use separate secrets for CI testing.
Automation Beyond CI
Dependabot / Renovate
yaml# .github/dependabot.yml version: 2 updates: - package-ecosystem: npm directory: / schedule: interval: weekly open-pull-requests-limit: 5
Build Cop Role
Designate someone responsible for keeping CI green. When the build breaks, the Build Cop's job is to fix or revert — not the person whose change caused the break. This prevents broken builds from accumulating while everyone assumes someone else will fix it.
PR Checks
- Required reviews: At least 1 approval before merge
- Required status checks: CI must pass before merge
- Branch protection: No force-pushes to main
- Auto-merge: If all checks pass and approved, merge automatically
CI Optimization
When the pipeline exceeds 10 minutes, apply these strategies in order of impact:
Slow CI pipeline? ├── Cache dependencies │ └── Use actions/cache or setup-node cache option for node_modules ├── Run jobs in parallel │ └── Split lint, typecheck, test, build into separate parallel jobs ├── Only run what changed │ └── Use path filters to skip unrelated jobs (e.g., skip e2e for docs-only PRs) ├── Use matrix builds │ └── Shard test suites across multiple runners ├── Optimize the test suite │ └── Remove slow tests from the critical path, run them on a schedule instead └── Use larger runners └── GitHub-hosted larger runners or self-hosted for CPU-heavy builds
Example: caching and parallelism
yamljobs: lint: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - uses: actions/setup-node@v4 with: { node-version: '22', cache: 'npm' } - run: npm ci - run: npm run lint typecheck: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - uses: actions/setup-node@v4 with: { node-version: '22', cache: 'npm' } - run: npm ci - run: npx tsc --noEmit test: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - uses: actions/setup-node@v4 with: { node-version: '22', cache: 'npm' } - run: npm ci - run: npm test -- --coverage
Common Rationalizations
| Rationalization | Reality |
|---|---|
| "CI is too slow" | Optimize the pipeline (see CI Optimization below), don't skip it. A 5-minute pipeline prevents hours of debugging. |
| "This change is trivial, skip CI" | Trivial changes break builds. CI is fast for trivial changes anyway. |
| "The test is flaky, just re-run" | Flaky tests mask real bugs and waste everyone's time. Fix the flakiness. |
| "We'll add CI later" | Projects without CI accumulate broken states. Set it up on day one. |
| "Manual testing is enough" | Manual testing doesn't scale and isn't repeatable. Automate what you can. |
Red Flags
- No CI pipeline in the project
- CI failures ignored or silenced
- Tests disabled in CI to make the pipeline pass
- Production deploys without staging verification
- No rollback mechanism
- Secrets stored in code or CI config files (not secrets manager)
- Long CI times with no optimization effort
Verification
After setting up or modifying CI:
- All quality gates are present (lint, types, tests, build, audit)
- Pipeline runs on every PR and push to main
- Failures block merge (branch protection configured)
- CI results feed back into the development loop
- Secrets are stored in the secrets manager, not in code
- Deployment has a rollback mechanism
- Pipeline runs in under 10 minutes for the test suite

