Order the ship-readiness steps for a production fine-tune

Shipping a **fine-tuned model** is not just "the eval score went up, push it." There is an ordering, and the ordering saves you money and outages. The guiding idea is cheap checks first, expensive checks last. Mechanical checks like "does the output parse as valid JSON?" cost nothing and catch obvious breakage, so they run first. Human evaluation on a golden set comes next, with a pass bar you agreed on before you looked at results. Then you guard against regressions. A fine-tune can quietly damage general ability, so you re-run benchmarks against the base model. You also check safety in both directions: it should still refuse harmful requests, but it should not start refusing harmless ones. Only after those gates do you spend real traffic. You A/B test against the current production model, load test for latency, and write down a tested rollback plan. Finally you promote the checkpoint and watch the dashboards closely for a day or two before calling it done.

The order follows one rule. Run the cheap, offline gates first, spend production traffic last, and have an escape hatch ready before you go live. Start by defining what "good" means, then run the offline gates cheapest-first. Schema and format validation is mechanical and catches gross breakage, so it goes first. Human evaluation on the in-domain golden set follows, scored against a threshold you fixed in advance. Then capability-regression against the base model on general benchmarks, then safety and refusal regression in both directions. Only a model that clears every offline gate earns expensive online testing. You A/B test against the current production model with enough samples for real statistical power. You load test with a realistic traffic mix and confirm p99 latency sits inside the service-level objective. Before promotion, stage and rehearse the rollback. Document the checkpoint to revert to and test the revert path on staging. Promote the fine-tuned checkpoint last, then watch the key metrics closely for the first 24 to 48 hours. Cheap checks gate the costly ones, and the rollback plan exists before any real user is exposed.