Others, who are much more qualified than me, may reply, but my understanding is that interop between Chez and Racket is not easy.

It depends on what you mean by interop. In Racket, you can call vm-eval and run things directly on Chez. But there are some restrictions on what invariants you have to preserve.

If you have a Chez library you want to use, you could build a mechanism using that to run it, but it would not be that easy.

Can you call chez functions in the same way you can call C functions?

(or vice versa)

that’s mostly what I meant with interop

It’s much easier than with C functions but there isn’t a library for doing it