AZ400-Q: decide whether to expand a feature rollout
A team exposes a new search experience to 10% of users with a feature flag. It must decide whether to expand the rollout based on adoption and failures. What telemetry design is best?
- A) Emit a custom event that identifies feature exposure/use, correlate it with request/failure telemetry, and compare the flagged cohort with the control cohort. ✓
- B) Count the number of lines changed in the search implementation.
- C) Read only the deployment approval comments.
- D) Disable all alerting while the feature is in preview.
Answer: A. Cohort-aware usage and reliability telemetry lets the team assess both adoption and harm before increasing exposure.
Why not the others: Code size and approval comments do not measure customer behavior. Disabling alerting removes the safety signal needed for progressive exposure.