Shipping fast but scared to refactor? I add the safety net your codebase is missing — unit, integration, and end-to-end tests with Vitest + Playwright, wired into CI so regressions get caught before your users do. I work test-first (TDD), so the tests describe your app's behavior instead of just chasing a coverage number. Proof: I raised a legacy React app from 4.82% → 97.19% coverage, and built 2,000+ tests (1,533 Vitest + 561 Playwright) for a multi-tenant SaaS — with quality gates that block bad code automatically. I don't modify tests to make broken code pass.