The LLVM ORC and Clang-REPL projects would be worth checking out if you haven't already: there's a healthy community of high performance computing folks working in this space over at https://compiler-research.org.

In particular, this talk might be interesting:

"Unlocking the Power of C++ as a Service: Uniting Python's Usability with C++'s Performance"

Video: https://www.youtube.com/watch?v=rdfBnGjyFrc Slides: https://llvm.org/devmtg/2023-10/slides/techtalks/Vassilev-Un...