Feature Flag Rollout

When rolling out a feature with feature flags:

1. Deploy the feature behind a flag, disabled by default.
2. Enable the flag for internal users or a test group first. Verify it works end-to-end.
3. Roll out to 5% of users. Monitor error rates, performance, and user feedback for 24 hours.
4. If metrics are stable, increase to 25%, then 50%, then 100% — pausing at each stage to monitor.
5. If issues appear at any stage, disable the flag immediately. The old code path handles all traffic.
6. Once at 100% with no issues for a full release cycle, remove the feature flag and the old code path.