Teams that release software by hand tend to release rarely, and each release becomes a risky event. CI/CD replaces that with an automated pipeline: every change is built, tested and made ready to deploy within minutes.

Continuous integration (CI)

Developers merge small changes into the main branch often — at least daily. Each change triggers an automatic build and test run. If something breaks, the team knows within minutes, while the change is still fresh.

Continuous delivery and deployment (CD)

  • Continuous delivery: every change that passes the pipeline is ready to release, and a person clicks "deploy".
  • Continuous deployment: passing changes go to production automatically.

Most teams start with continuous delivery and move towards automatic deployment as confidence grows.

The stages of a good pipeline

  1. Checkout and install dependencies from a lockfile so builds are repeatable.
  2. Lint and type-check to catch mistakes early.
  3. Unit tests — fast, run on every push.
  4. Build the application or container image once, and reuse that exact artifact in every later stage.
  5. Security checks — dependency vulnerability scan and secret detection.
  6. Integration or end-to-end tests against a real database in a temporary environment.
  7. Deploy to staging, run smoke tests.
  8. Deploy to production with a strategy that limits risk: rolling, blue-green or canary.
  9. Verify and monitor, with an automatic or one-click rollback.

Database changes

Schema migrations deserve special care. Keep them additive where possible (add columns before removing old ones), review them like code, back up before applying them, and never let an application silently change the schema on start-up.

Metrics worth tracking

The four DORA metrics give a balanced view of delivery performance:

  • Deployment frequency — how often you release
  • Lead time for changes — from commit to production
  • Change failure rate — share of releases that cause problems
  • Time to restore — how quickly you recover from a failure

Starting small

You do not need everything on day one. A good first pipeline runs lint, unit tests and a build on every pull request. Add automated staging deployment next, then production deployment with a rollback, then more tests over time.

Key takeaways

Integrate small changes often, build once and promote the same artifact, test at several levels, deploy with a rollback plan, and measure delivery with the DORA metrics.