CI/CD pipelines that catch problems before customers do

A green pipeline feels like proof. Often it's just proof that nobody wrote the test that would have failed. Continuous integration and continuous delivery only protect production when the pipeline blocks the right things: failing tests, vulnerable dependencies, missing migrations and builds that can't be reproduced.

This section looks at what a pipeline should stop, what it should only warn about, and how to keep it fast enough that people don't route around it. We'll cover build caching, test tiers, artifact versioning, secrets handling in CI logs, approval gates for production, and the real difference between continuous delivery and continuous deployment.

We're also skeptical of automation for its own sake. Auto-deploying every merge to production is a choice with trade-offs, and for plenty of teams a one-click manual promote with a tested rollback is the more reliable setup. We'll say which one fits when.