What's the point? Why not write everything in Nim?
If you depend on certain Python libs that's understandable. But it should not be too hard to translate them to Nim since the syntax of Python and Nim are not very different.
If a company has a significant amount of existing code in Python, no sensible engineering manager will agree to a complete re-write of the existing code-base. It would divert resources from more-pressing functionality (new features, bugfixes, etc) and almost certainly introduce its own new bugs due to the complete re-write.
This would be the case whether you schedule the re-write in a single blocking development effort (in which case, all forward progress would stop during that time) or broken into batches over time (in which case, it will be much longer until the new system is ready, and the old system will be a moving target as it continues to be developed).
Instead, the chances of a Nim-integration being beneficial to the company (and thus, your chances of getting approval from your engineering manager) are MUCH higher if you can simply write NEW functionality in Nim (or occasionally re-write small, self-contained inner loops in Nim) and the new Nim code integrates smoothly into the existing Python as a Python module.
This is the approach I've taken at my company (with my engineering director's approval).
In theory, you could even use skunkworks-Nim in your large Python codebase, as long as your Nim code presents itself as a good-citizen Python module, much like the tales of skunkworks-Scala being used in large Java codebases.
I am not talking about a complete rewrite of big business software written in Python. I just had small projects in mind which are typical for Python. Big business usually depends on Java, C# and C++ but not on Python.
Yeah, Python has a huge ecosystem of amazing libs. Many are actually C libs with Python bindings, so they're fast. It would be very time consuming to port them to another language.
If you depend on certain Python libs that's understandable. But it should not be too hard to translate them to Nim since the syntax of Python and Nim are not very different.