After using gevent for about a decade I have started using asyncio for new projects, just because it's in the standard library and has the official async blessi

After using gevent for about a decade I have started using asyncio for new projects, just because it's in the standard library and has the official async blessing of the Python gods. Indeed it is way harder. I'm always coming up against little gotchas that take time to debug and fix. Part of me enjoys the challenge of learning something new and solving little puzzles. It's getting easier, especially as I build up a collection of in-house async libraries for various things. As for performance, it's not too bad for mostly io bound tasks, which is why one uses async in the first place. Some tight loop benchmarks for message passing with other processes show it to be about half the speed of gevent in my case, which is fine. It's nice to be able to deploy async microservices without installing gevent, and there's a certain value to the discipline that it imposes. I like how I am able to bring non-async code into the async world using threading. I imagine the performance would improve quite a bit with pypy, perhaps exceeding that of gevent. Gevent makes it so damn easy, I've been spoiled. I was disappointed when asyncio came out, as I would have preferred the ecosystem moved in the gevent direction instead; but I'm coming around. It's super annoying how the python ecosystem has been bifurcated with asyncio. You really have to choose one way or another at the beginning of a project and stick with it. And yeah, async programming (in Python) isn't really for CPU bound stuff. You might benefit from multiprocessing and just use asyncio to coordinate, which is what it excels at. PyPy can really help with CPU bound stuff too, if the code is mostly pure Python.