Ask HN: How are things like v0.dev built?

I'd like to understand more how one would build/iterate over things like v0.dev. Is it LLM? Is it some fine tuned model? Or some other generative AI?

Are there some dev/eng blogs/papers around it, and similiar?

It's very interesting topic to me but essentially black box.

Someone just released an open source implementation of v0 https://github.com/rapidpages/rapidpages