How do you build an evaluation harness that runs in CI to gate every model change?
A green build says nothing about model quality. The signal is an eval harness that runs deterministically in CI, checks against a frozen baseline, and blocks the merge on regressions. Here is how to make it fast, stable, and trusted.
Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.
A green build says nothing about model quality. The signal is an eval harness that runs deterministically in CI, checks against a frozen baseline, and blocks the merge on regressions. Here is how to make it fast, stable, and trusted.
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.
