GitHub epitomizes a "culture of shipping" to me. They're slamming feature after feature out the door (multiple features in the same day sometimes - like today). I like BitBucket too but, man, I would not want to be competing against the GitHub team right now. They're just prolific.
But I would also say they do have a rather largeish dev team: https://github.com/about/team. Like 50-80 devs maybe? Thats like 12-20 teams of four people each.
Plus they have some really productive people on their team, several people are/were core contribs to Rails.
I guess one would expect with that many high quality people that a decent amount of work would be getting done.
Our team makeup is almost entirely "devs" (I call them Engineers — people who design, build, and ship software). A lot closer to 120 than 80. However your estimates a pretty far off in terms of people who work on dotcom — that number is much closer to 15.
One of the more interesting sociological problems of software to me is this idea that more people equals faster movement. The only studies in this field prove the opposite, yet common opinion is simply that: more people equals more output. We've actually spent a great deal of effort not growing our team lately, much of which has directly contributed to an increase in pace.
Our work is still primarily client based at Lincoln Loop and we share many of the same principles that GitHub does. Keeping track of billable hours is how we get paid, but our people get to choose when, where, and how many hours they will bill. We've written a little about it here: http://lincolnloop.com/blog/categories/business/
This is part of a larger scheme by Github to get you to start writing text and code directly into the website. This is just another nice, small editor improvement.
