DevOps
CI/CD Pipelines Explained: Ship Code Faster and More Reliably
By Riazul Islam•
Summary: Still deploying code manually? CI/CD automates testing and deployment so you can ship faster with confidence.
## What Is CI/CD and Why Should You Care?
**CI (Continuous Integration):** Every code push is automatically tested.
**CD (Continuous Deployment):** Every passing test automatically deploys to production.
Together, they eliminate the "deploy day" stress and catch bugs before users see them.
### A Simple CI/CD Pipeline
```
Code Push → Run Tests → Build → Deploy → Monitor
```
### Setting Up with GitHub Actions
```yaml
name: CI/CD Pipeline
on:
push:
branches: [main]
pull_request:
branches: [main]
jobs:
test:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- uses: actions/setup-node@v4
- run: npm ci
- run: npm test
- run: npm run lint
deploy:
needs: test
if: github.ref == 'refs/heads/main'
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- run: npm ci && npm run build
# Deploy step here
```
### Testing Strategy for CI
1. **Unit tests** - test individual functions
2. **Integration tests** - test API endpoints
3. **E2E tests** - test user flows (Cypress/Playwright)
4. **Linting** - catch code style issues
5. **Type checking** - TypeScript compilation
### Deployment Strategies
**Rolling deployment:** Replace instances one at a time
**Blue-green:** Run two environments, switch traffic
**Canary:** Deploy to 5% of users first, then roll out
### Key Metrics to Track
- **Deployment frequency** - how often you ship
- **Lead time** - code commit to production
- **Failure rate** - % of deployments that fail
- **Recovery time** - how fast you fix failures
**The best teams deploy multiple times a day. CI/CD makes that possible.**