Compare Rollback Speed With and Without a Registry

A newly promoted recommendation model is causing a measurable drop in click-through rate 20 minutes after promotion. The on-call needs to revert to the previous model as fast as possible.

1. Describe the rollback procedure in a registry-based setup, including roughly how long it should take and why.
2. Describe the rollback procedure in the bucket-of-files setup from this subject's opening scenario, and identify each step where delay or error is likely to creep in.
3. Beyond raw speed, what's the qualitative risk difference between the two rollback procedures during an active incident, when people are working quickly under pressure?