[ggregoire]

> Is anyone actually using FastAPI in a commercial, large scale app? Would you prefer using...say Django or Flask + Gevent (since they're more mature) over FastAPI?

Django and FastAPI are two different things. The former is a huge and opinionated MVC-like web framework and the latter is a simple library to make HTTP endpoints. I prefer FastAPI but it really depends of what you are building and how many people are going to work on that API.

> What's odd for me is that the React website also asks you to pick between either Next.js or Remix[3].

It's indeed very odd, they made this change with the new doc. I would not recommend to pick any of those and just start your project with vite.js, so you can focus on React and keep it simple. You can use react-router for the routes and react-query to call your backend. You don't really need anything else.