What is CI/CD?
Continuous Integration (CI) means every code push automatically triggers a build and test run. Bugs are caught immediately, not days later.
Continuous Delivery (CD) means every passing build is automatically packaged and ready to deploy. With Continuous Deployment, it's deployed to production automatically without human approval.
Developer pushes code
↓
CI: Build + Test
↓
CD: Package artifact
↓
Deploy to staging
↓
(optional gate: manual approval)
↓
Deploy to production
Benefits
| Without CI/CD | With CI/CD |
|---|---|
| "Works on my machine" | Tested in a clean environment every time |
| Integration hell before release | Integrate continuously, small batches |
| Long, risky deployments | Short, automated, predictable deployments |
| Blame when things break | Clear audit trail, fast rollback |
CI/CD Platforms
- GitHub Actions — built into GitHub, YAML-based, huge ecosystem
- GitLab CI — built into GitLab, very powerful
- Jenkins — self-hosted, highly configurable
- CircleCI, Buildkite, Drone — alternatives
The Feedback Loop
The most important property of a CI pipeline: fast feedback. Developers shouldn't wait more than 10 minutes to know if their change broke something.
Run the fastest checks first (linting, type checks) so failures surface immediately without waiting for a full test suite.