Customers report slow checkout pages that began right after a deployment. The incident commander is already in the channel. Under standard incident response practice, which action comes first?
Show answer and explanation
Answer: C
Incident response prioritizes stopping user harm. When a recent change is the likely trigger, the fastest mitigation is often a rollback, shifting traffic away from the affected version, or disabling a feature flag. Root-cause work, timelines, and communication matter, but they can wait until customers are being served correctly again. Investigating first lengthens the outage for every user still hitting slow pages.
Why the other options are wrong
- A. Pinpointing the offending line can take hours. Doing it before mitigating keeps customers on the slow pages for that whole time.
- B. Postmortem notes are valuable, but a timeline document does not reduce user impact. It should be started, though not ahead of mitigation.
- D. Keeping leadership informed is part of incident communication. It is not the first technical step, and a briefing does not restore checkout speed.