Scoping AI changes
The single biggest cause of AI-induced damage is letting it change too much at once. A 400-line diff across nine files is impossible to review and easy to hide a bug in.
Keep changes small and contained:
- Ask for one logical change at a time, not "while you're there, also..."
- Tell it explicitly: "Only touch
src/auth.js. Don't refactor anything else." - working states often, so you always have a clean point to roll back to.
- When it proposes a big rewrite, ask it to break the work into steps you can review one by one.
Small scope makes the next step — reading the diff — actually possible. There's a compounding effect here: small commits are also small blast radii. If a tightly scoped change turns out to be wrong, you revert one commit and lose ten minutes. If a sprawling change is wrong, you either spend an hour untangling which part broke things, or you throw away an afternoon of work. Scope discipline is cheap insurance you buy before you know you'll need it.