Lesson 14 / 23
Dev / Staging / Production
Promote changes through dev, staging and production environments with automatic or manual gates.
The promotion flow
A typical flow: dev (fast, unstable, for developers), staging (a production-like copy for final checks), production (real users). A build is promoted from one to the next only after it proves itself.
Gates between environments
Moving to the next environment is gated — automatically by passing tests and health checks, or manually by a required approval — so a bad build can't silently slide into production.
Dress rehearsal
Staging is the dress rehearsal before opening night: same script, same set, same lighting as production — just no paying audience yet. If it goes wrong here, the real audience never sees it.