Multi-file refactors are the highest-leverage and highest-risk agent task. These topics cover scoping, checkpoints, and review discipline.
3 answers
Asked for a null check in one function. Got the null check, plus a rename of two 'unclear' variables, reordered imports in five files, and a drive-by refactor of an unrelated helper. Every diff needs a line-by-line audit for stowaways.
Asking for a whole file back — a long migration, a generated fixture, a full rewrite — fails outright instead of truncating. The fix is to stop asking for one enormous message.
Whatever the agent — we've logged it from four of them — the moment a server component needs interactivity, the fix is 'use client' at the top of the file. Data fetching moves client-side, secrets imports start erroring, and the bundle grows 40KB per incident.