It is part of mypy, and it compiles type-valid python files to cpython binary extensions, and takes advantage of a lot of shortcuts available to cut execution time. It is still a bit early to advocate for its use everywhere, and has it drawbacks (extensions compiled with mypyc will also typecheck the inputs and outputs of the module at runtime, which is great for improving code quality and validity of the annotations, but also means you may get TypeErrors in production if you hit a bad edge case).
If there is no shortcut it will fallback to normal, slow, python performance, with some smallish benefits (e.g. vtables for attribute lookups, no parsing time, etc).
Not exactly what you're talking about, but... For some types of functions, Numba's JIT offers some pretty nice speed ups. It can infer function types (or you supply them yourself) and compiles to optimized machine code
It's tricky, since only the typed part can be sped up, and there will usually be lots of back-and-forth between typed and untyped code; which requires conversions and checks.
Python would probably be even worse, since it's "more dynamic" than Racket; e.g. there are many hooks that can run arbitrary code (like dunder methods), and there's little encapsulation so values may get swapped out via monkey-patching at any time.
