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
# .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
integration:
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:${{ secrets.CI_DB_PASSWORD }}@localhost:5432/testdb
Note: Even for CI-only test databases, use GitHub Secrets for credentials rather than hardcoding values. This builds good habits and prevents accidental reuse of test credentials in other contexts.
E2E Tests
e2e:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- uses: actions/setup-node@v4
with:
node-version: '22'
cache: 'npm'
- run: npm ci
- name: Install Playwright
run: npx playwright install --with-deps chromium
- name: Build
run: npm run build
- name: Run E2E tests
run: npx playwright test
- uses: actions/upload-artifact@v4
if: failure()
with:
name: playwright-report
path: playwright-report/
Feeding CI Failures Back to Agents
The power of CI with AI agents is the feedback loop. When CI fails:
CI fails
│
▼
Copy the failure output
│
▼
Feed it to the agent:
"The CI pipeline failed with this error:
[paste specific error]
Fix the issue and verify locally before pushing again."
│
▼
Agent fixes → pushes → CI runs again
Key patterns:
Lint failure → Agent runs `npm run lint --fix` and commits
Type error → Agent reads the error location and fixes the type
Test failure → Agent follows debugging-and-error-recovery skill
Build error → Agent checks config and dependencies
Deployment Strategies
Preview Deployments
Every PR gets a preview deployment for manual testing:
# Deploy preview on PR (Vercel/Netlify/etc.)
deploy-preview:
runs-on: ubuntu-latest
if: github.event_name == 'pull_request'
steps:
- uses: actions/checkout@v4
- name: Deploy preview
run: npx vercel --token=${{ 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.
// 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:
# 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
# .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
jobs:
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: