A feature flag controls which users see a given version of a feature. It lets new code reach production without immediately exposing it to everyone. section 5.6
Release to a small group first
A team pushes new code to the main branch, then directs most users to the old version while exposing the new version only to the developer and quality-assurance team. After validation, it removes the old code and sends every user to the new version. section 5.6
Use the flag as part of a controlled delivery process:
- Deploy the new implementation while keeping most users on the existing implementation. section 5.6
- Expose the new implementation to a small validation group, check that it works, and switch everyone over only afterward. section 5.6
- Pair the rollout with automated tests; the flag supports trunk-based development but does not replace validation. section 5.6
