I haven't seen that too much, but I do have guardrails. I use Deno and run 'deno lint' as part of the build. It doesn't allow 'any'.

Also, I tend to ask planning questions, like "how would you implement this" and "what would the API changes be?" I'm picky about API's. Lately I've been using Deno workspaces (multi-package repos) and tell it when to make a new package or a new entrypoint. Maybe that helps?

If I just ask for features and don't look at the code, it will definitely make a mess, though. (A working mess, but it takes a while to refactor my way out.)

They're improving but you definitely need both a strong AGENTS.md and also usually many LLM passes (one for implementing a feature, another one for code quality, large passes every now and then for major refactors, etc).

That's not really a typescript thing though, just an LLM thing.