This, with TypeScript strictness cranked all the way up. MUI for the component library, plus Playwright for integration-testing and hoverfly to stub/fake/mock the backend, and Open-API to define the APIs between app -> bff -> backend.

This stack, plus claude-code, with the whole project fully automated (i.e. claude-code run all the parts easily) - is a literal productivity super-power. You can crank out entire complicated LoB apps, 10 - 30 pages of distinct, medium-complicated functionality in about a week, if not less - instead of weeks or months. Fully tested, production-ready codebase, not prototype-tier/vibe-code.