The article only barely touches the performance reason for async. Without an explanation of that vs OS threads, it doesn't make much sense what you're trying to

The article only barely touches the performance reason for async. Without an explanation of that vs OS threads, it doesn't make much sense what you're trying to accomplish with async. And while you can think of it as the caller having control like the article says, you can also think of it the more typical way, that you're issuing work and getting async responses. So I would still start at https://rust-lang.github.io/async-book/01_getting_started/02_why_async.html https://rust-lang.github.io/async-book/01_getting_started/02... And if you want to go deeper, think about how you'd build a massive IO-bound server without async (the answer will look like async but with extra steps).