Smart, boring people and no balance.
Pros
The people are smart, and the scaling challenges are great. Where else does your code impact a billion people? The compensation is amazing. Senior management are generally amazing people, smart, visionary and compassionate.
Cons
The focus on measuring means anything that can't be measured is ignored. It's easy to measure someone's ability to code on a whiteboard. As a result, the coders are much better than nearly everywhere I've worked, but that's it. Social skills and personality can't be measured. As a result there is no one here you would ever be friends. The internal surveys bear this point that people don't have friends at work. Similarly for managers, they are selected strictly for their technical ability. Again, they have zero compassion. In my time being here, I've never once felt like anyone cared if I was here or not. Not once has anything positive ever been said. It's really astounding. Recruiting does an amazing job at making candidates feel wanted. That feeling disappears the moment you sign. After that, you have no manager or anyone who will care. You'll go into bootcamp where you'll have a "mentor". His role is to continue to do his job while counting the number of lines in your diffs to make sure you can make progress with no assistance. After bootcamp, you'll have a manager who operates in the same mode. They are interested in the technology and not the people. To them, you are a resource to be maximized. They will tell you everything you need to do to improve, but never once say "good job". In boot camp, I kept meeting these amazing, visionary dynamic managers. I know realize they were the exception. Those people made me love Facebook during bootcamp, but that feeling wore off quickly once I interacted with the average line level manager. Plus, beware of the reviews here. Recruiting will tell you point blank that they curate these reviews. The reason FB has the highest rating is because someone internally has a goal to achieve certain star ratings on this site.