Twitter employs 'about 900 people'

"Last month Twitter CEO Dick Costolo said that the company now employs “about 900 people”. I’ve been tracking Twitter’s staff count pretty closely for a few years now, and while it’s certainly true that Twitter’s hiring spree is on a major uptrend, with some serious growth in the past few weeks, either Costolo rounded up a little, or Twitter themselves are slow to update their own data, because their current roster looks to be set at 833 people."

Source:  MediaBistro, 9th February 2012