Other design decisions that made uv fast:

- uncompressing packages while they are still being downloaded, in memory, so that you only have to write to disk once

- design of its own locking format for speed

But yes, rust is actually making it faster because:

- real threads, no need for multi-processing

- no python VM startup overhead

- the dep resolution algo is exactly the type of workload that is faster in a compiled language

Source, this interview with Charlie Marsh: https://www.bitecode.dev/p/charlie-marsh-on-astral-uv-and-th...

The guy has a lot of interesting things to say.

> real threads, no need for multi-processing

parallel downloads don't need multi-processing since this is an IO bound usecase. asyncio or GIL-threads (which unblock on IO) would be perfectly fine. native threads will eventually be the default also.