Pros
Really good benefits (health care, free meals/snacks, gym, student loan benefit). Really great/interesting people in a lot of different departments. Things happen quickly with technology when they need to improve. Lots of interesting tech. Lots to do (interesting projects) and lots to learn. Good options to move around if the timing is right for a lot of people.
Cons
High stress (high reward, high stress). This leaks into every area of the business. Sometimes it feels like everyone has ADD. Rushing around to and fro. High turnover, people come and go. Really just the effects of a high-pressure growth environment, but it can get disheartening. No performance reviews, very little feedback on work or training. It can get very loud and chaotic, lots of distractions. Very political environment, especially with promotions/raises. etc.