One of the things I've heard about FB is the complete lack of change control. That, at least on mobile, people will add code with almost no oversight, which has lead to the apps having such huge numbers of classes.
They still have change control, they just have thousands of people committing to it and as long as it works it ships. Still lots of individual CCRs. Change control doesn't mean you get a decent end product, just that you have a log of who did what.
