HPC software developer.
Python is fast to write and deliver results, but it is not a good choice when you cannot sacrifice any runtime. It is the time to switch to C++. But we certainly don’t want to give up the productivity available to Python, and we worry about the complexity of C++. The way to go is to design the backbone system in C++ and expose the API in Python. Then we can enjoy the capabilities coming from the complex compiler and scripting it just like Python. (Actually it is Python.)