Pros
Smart people. Like, seriously crazy-smart. But also friendly and helpful. A start-up with a start-up atmosphere...but 1000+ employees so without the start-up rollercoaster. Cutting edge technology in the fast growing field of big data processing and analytics = great resume fodder. Lots of room for personal advancement. Good room for work/life balance. (Although I'm remote...if you are working at the headquarters in Palo Alto you might have a different experience.)
Cons
The technology is growing and changing so fast it's hard to keep your head around it all; it can be overwhelming and disheartening to realize stuff you mastered six months ago is now obsolete. The company is also growing and there are the usual growing pains. It can be hard to find "experts" to help you, not because they don't wish to be helpful, but because they are thin on the ground, as half the company was hired in the last 12-18 months. Also everyone is busy, there's way more work to go around than people to do it, so you have to set firm personal boundaries to maintain good work-life balance: no one is going to prompt you to stop work at the end of the day or take a vacation.