One thing I always found odd about DE Shaw is how casual the work environment is. It's like google, but in Manhattan. The problem is NY isn't california and quant finance isn't all software. There's a certain pace and overt competitiveness to Manhattan that enforces a discipline and a work ethic onto people. This works quite well in the Darwinian world of finance. But, from what I saw of various parts of DE Shaw's operations there was somewhat a lack of urgency to some fairly critical areas. A good firing spree every once in a while seems to work wonders in putting the urgency back into the workforce.