At my old gig we ran Django and FastAPI with pypy. I don't remember there being too many issues. One thing is that pypy versions lag behind official python, so

At my old gig we ran Django and FastAPI with pypy. I don't remember there being too many issues. One thing is that pypy versions lag behind official python, so if you're using bleeding edge stuff, it won't be supported in pypy yet. That was a couple of years ago at this point, and I've not been in the python ecosystem since then, but I can only imagine things are getting better in that regard rather than worse.