This somewhat mirrors my own development. I started in C, and am still in it for systems/OS development at work. In UI development, we had older C toolkits, b

This somewhat mirrors my own development. I started in C, and am still in it for systems/OS development at work. In UI development, we had older C toolkits, but are replacing them with newer toolkits that are C++. I started off trying to just do C business logic with some C++ glue code for the UI. Sticking to what's familiar. In the end, it was just easier to do everything properly. All C in areas that are C. All C++ in areas that are C++. Same with C#. Trying to mix them is just more work than necessary. At least I get to add C++ to my resume. There is a little joke at work, w.r.t. our existing codebases and code choices. They are career-driven choices, not technical choices. The result is a mess of a codebase, but I'm fully embracing that now.