Your production model decayed. Is it data drift, concept drift, or a pipeline bug, and how do you tell them apart?
'The model got worse' can mean three very different things with three different fixes. Retrain a model that a pipeline bug actually broke and you just bake in garbage. Here is the order to triage it in.
Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.
'The model got worse' can mean three very different things with three different fixes. Retrain a model that a pipeline bug actually broke and you just bake in garbage. Here is the order to triage it in.
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.
