Google (at least the good parts) has a pretty good culture of documentation, which helps a bit. While it drove me batty to need to spend a month writing up 10 p

Google (at least the good parts) has a pretty good culture of documentation, which helps a bit. While it drove me batty to need to spend a month writing up 10 page specs and getting sign off from directors for a minor feature that nobody would see and would take 3 days to code up, it was nice to be able to trace through the historical evolution of abandoned features when trying to figure out how they worked. No idea if Facebook is similar.