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.
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.
I would credit our pace far more to the organizational structures we've created within our company (ex: http://tomayko.com/writings/adopt-an-open-source-process-con...) than the size of our team.
I've always wondered, how can companies that do client work adopt those principles? Is it even possible?