I had a very similar experience, sans the degree, but in the embedded world for an RF company. I still like to write C in my free time today, nearly 8 years after leaving that job. I've shipped a few pieces of performance critical code in C for the Rails shop that I work for today, too, in the form of FFI and language extensions. I honestly don't think I'll ever ~be free from~ give up C explicitly for these reasons (it's also ludicrously satisfying to realize and share these sorts of performance gains in a production application).