Oh, I can imagine, ASGI must be immeasurably easier. Where do the async speedup gains come from, though, if your database is still sync? Wouldn't threadpools provide comparable performance before?
For WebSockets, all of the code is async, so I'm already using `asyncpg` for any database stuff that is happening there.
With regards to why are the sync endpoints faster, I think it is a number of things, some of which are userland changes that could've been made under Flask, but all of which are somewhat related to the switch. With regards to things that FastAPI itself has changed, I think using a (de)serialization lib like Pydantic and serializing to JSON by default (which is what we were doing under Flask anyway, though with Marshmallow) makes a lot of the code paths in the underlying lib a bit faster, because with Flask there was more "magic" going on behind the scenes. For userland stuff, I think partly because there is less magic going in the background (I really like FastAPIs dependency injection system), it's made it easier to identify the bottlenecks and optimize hot code paths.
That makes perfect sense, thank you. I love FastAPI just for the code clarity and ease of working with better type objects (the Pydantic classes) alone, though the speed benefit is nice to have too.
