You need to move a live feature to a different model or provider. How do you cut over without a quality regression?
A provider swap does not fail with a 500. It fails by staying up and quietly getting worse. The signal is knowing what actually changes under you on a model swap, and the shadow-plus-staged-ramp protocol that catches it before your users do.
Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.
A provider swap does not fail with a 500. It fails by staying up and quietly getting worse. The signal is knowing what actually changes under you on a model swap, and the shadow-plus-staged-ramp protocol that catches it before your users do.
Lead with where the obvious approach breaks, because that is the judgment they are screening for — most candidates jump straight to the happy path and lose the room.
Then walk the failure back through the pipeline in order, naming the one metric the customer's exec sponsor actually cares about before you propose the fix.
