I think the point of Async IO is not to go faster, but to be able to server more requests in a single process. This is only possible when request time is mostly

I think the point of Async IO is not to go faster, but to be able to server more requests in a single process. This is only possible when request time is mostly spent waiting for I/O. So if you have some server and you want to handle hundreds of thousands of concurrent requests, and each requests takes a few hundred milliseconds and most of this time is waiting for I/O (e.g, waiting for other micro services to reply), then using Async IO you could do this in one single box. Yo probably won't be able to do that with a typical balanced process pool such ash uwsgi or gunicorn.