CI/CD pipelines that prove something before they ship it

A green checkmark only means the steps you wrote passed. Whether those steps tell you anything about production is a separate question, and it's the one this section cares about.

We cover continuous integration and continuous delivery with GitHub Actions, GitLab CI and similar tools: building once and promoting the same artifact, running tests that match how the app is really used, gating deploys on approvals where it makes sense, and keeping secrets out of logs. We also look at the less exciting parts, like caching dependencies, pinning action versions and making a failed pipeline easy to read at a glance.

Continuous deployment, where every merged change goes live automatically, can work well. It works best when monitoring and rollback are already in place, so you'll see us link back to production readiness a lot. A fast pipeline that ships broken releases quickly isn't an improvement.