> Today I manage a 400,000-line system in C++.

On your own? If yes, then that's pretty impressive. My previous team maintained 350,000-line Perl application with at least 5-6 programmers. If you're handling that C++ system alone, I'd assume it's pretty self-contained, since the complexity in large systems regularly comes from all the other systems that you interface with (at least for the aforementioned Perl app).