While usually pitched as "only" a language for fast extension modules and/or bindings to existing C/C++ code, Cython is really a language in its own right. https://cython.org/ has some more details.
It works by generating C code that calls the regular CPython API, managing all the ref count and tuple jazz that's rather a hassle to write in C directly. Then you run a C compiler against this code and it literally just links against the CPython .so's/DLLs. So, it's not just calling module code the same way as CPython, but actually calling the core built-in to Python code the same way as well.
As you add more `cdef` type annotations to your cython code, the generated C code becomes closer & closer to hand-written C code (both in hazards and efficiency).
Of course, a caveat is that may be Cython also doesn't improve upon Python very much as a language, except for allowing gradual static typing.
There's a good Python -> Nim bridge: https://github.com/yglukhov/nimpy
https://github.com/vindarel/languages-that-compile-to-python
What management like very much is that using F# attracts better talent, but they no can believe.
It has great package/environment management, excellent (potentially close-to-C) performance, automatic type inference, and a good set of interactive tools that make for a rich REPL.
But any such FFI (from any language) is an additional point-of-failure, an extra gear that could break and has to be maintained. And on the con side of Julia, there's an initial compilation time (which is improving version to version, but still a factor to consider).
Also it should be mentioned that the advantage of Python is not only its ecosystem of libraries, but also the vast array of tutorials and learning resources, and of development tools. Those are areas where most other languages have to play catch-up with Python, especially a relative newcomer like Julia.
[1] https://github.com/cjdoris/PythonCall.jl [2] https://github.com/JuliaPy/PyCall.jl/
I tend to stick to vanilla python though, mainly because Hy is too much of an hassle for my use cases.