MeetMate Web v4 — A New SPA Forked from a Legacy RN Monorepo
Without any service downtime, I forked a React 19 SPA out of an RN+Electron monorepo and, as the sole frontend engineer, went from login through 7 batches of host features in one month. In the final stretch I got the regression-guard round to pass, removed 89,724 lines of v3 legacy code in one sweep, and finished with Web v4 as the single target (the backend was handled by a separate teammate).
- Migration completed — after passing the regression-guard round (18 WebSocket domains + 5 member-seed cases blocked), I removed 1,233 files / 89,724 lines of v3 legacy code on the same day.
- 475 → 0 FSD boundary violations. Enforced in both lefthook and CI, so it can't break the same way again.