[uniqueuid]

I don't have a book recommendation ready, but if you want to see how async can be used in a large codebase, have a look at the telethon [1] library. It's a python library for telegram and one of the few that actually implement MTProto. It's huge, generates a large chunk of its machinery automatically from the MTProto specs and is extremely (!) well structured.

This is much more useful than the typical "let's write a single-run example with async" blog post.

[1] https://github.com/LonamiWebs/Telethon