PAT 06
IMPLEMENTATION PATTERN
Feature-flagged model change
A model or prompt change reaches every user before its actual operating effect is understood.
Changing a model, prompt, retrieval strategy, tool permission, or structured-output contract.
REQUIRED CONTRACT
Keep these visible.
- 01Named cohort
- 02Exposure limit
- 03Stop signal
- 04Prior version available
AVOID
Do not hide the failure.
- Percentage without identity
- No rollback owner
- Mixed evaluation versions
- Permanent canary
Prove the boundary.
Route a known cohort to the new version, force the stop signal, and confirm traffic and state return safely.