Yep, that about sums it up. gevent can't monkeypatch synchronous code that's implemented in non-Python native modules, but I think pretty much all native Python

Yep, that about sums it up. gevent can't monkeypatch synchronous code that's implemented in non-Python native modules, but I think pretty much all native Python libraries struggle with those sorts of things, and asyncio of course also can't deal with it. The vast majority of the time, gevent's monkeypatching works without any issues. With asyncio, you basically have to rewrite everything from the ground up to always use the new async APIs, and you can't interact with libraries that do sync I/O.