Interesting re complex projects. Compared to other langs I've used, rust gives me more confidence in maintaining and refactoring complex projects, maintaining state etc. I think this is due to the strict type checks, the helpful compile errors, and the ownership system. Maybe also due to the robustness of what I call struct-and-enum-oriented programming.

I have plenty of my own beefs with rust that I won't go into here, but... it comes out on top for complex projects.