GroundControl

Many people think that feature flags are only useful for enabling features for specific users. But they can be used for many more things.

• For building features. Instead of doing long-lived branches, put unfinished functionality behind a feature flags, so it's shipped but not accesible to users. This has many benefits: less merge conflicts and your teammates can enable the flag and test the work in progress without impacting end users.

• For deploying risky changes. If a change is risky, include the old and new version in the code and switch the code path with a feature flag that you can control remotely. It's way faster to roll back this way than rolling back the whole deployment.

• For A/B testing. Ship two versions of something and enable one version to 50% of users, then gather metrics.

• For performance optimizations. Ship two versions of a functionality and measue which one is faster or uses less resources.

• For incident mitigations. Disable parts of your app in case of an incident using feature flags, instead of going completely down.

• For sunsetting features. Disable a feature for everybody except for a few users that are still using a deprecated feature.