model registry

A textbook screen with a non-textbook scoring rubric. Naming Tracking, Projects, Models, and Registry gets you a pass, knowing which component nobody actually uses, and why, gets you the offer conversation.

The trap is that S3 versioning sounds like a complete rebuttal, it isn't, and interviewers at banks know exactly why. What a registry adds that storage never can, and the audit question that decides regulated-industry offers.

A real interview question designed to catch resume inflation: candidates say 'we promote to production' and can't name the API call. What actually moves when a model is promoted, and the answer that proves you've done it.

Databricks-stack interviewers use this to date your knowledge: describing Staging→Production stage transitions marks you as two years behind. The alias-based promotion flow (@champion/@challenger), gate by gate, with the access-control detail most answers miss.

Reported from JPMorgan's MLE loop, and graded on one distinction most candidates miss: rollback is a capability you build before the incident, not an action you improvise during it. The pointer-flip mechanics, the auto-trigger debate, and when rollback itself is unsafe.