[mixmastamyk]

It compiles different files separately, right?

With some exceptions for core data structures, it seems that if you only modified a few files in a large project the total compilation time would be quick no matter how slow the compiler was.

[conradludgate]

Sorta. The "compilation unit" is a single crate, but rustc is now also parallel, and LLVM can also be configured to run in parallel IIRC.

Rust compile times have been improving over time as the compiler gets incrementally rewritten and optimised.