Comment by Culonavirus

Generally speaking, "LLMs" that I use are always the latest thinking versions of the flagship models (Grok 3/Gemini 2.5/...). GPT4o (and equivalent) are a mess.

But you're correct, when you use more exotic and/or quite new libraries, the outputs can be of mixed quality. For my current stack (Typescript, Node, Express, React 19, React Router 7, Drizzle and Tailwind 4) both Grok 3 (the paid one with 100k+ context) and Gemini 2.5 are pretty damn good. But I use them for prototyping, i.e. quickly putting together new stuff, for types, refactorings... I would never trust their output verbatim. (YET.) "Build an app that ..." would be a nightmare, but React-like UI code at sufficiently granular level is pretty much the best case scenario for LLMs as your components should be relatively isolated from the rest of the app and not too big anyways.