The entire IOTA watches firmware is written in C++ for efficiency and speed. Our source code (45,000 lines) obeys best OOP practices of abstraction and encapsulation. We take our time to write good embedded code, code that does not leak memory, code that can run in 320kb of RAM without any heap corruption, it even looks pretty. For the end user it simply means a stable system.
Here’s a screenshot of some of our source code, because it also looks tidy 🙂 :