A mature culture of smart people working on the hardest and most rewarding problems
Pros
The Culture: This tops the list of reasons to work at Facebook. Many companies say they take their culture seriously but Facebook lives it. The mantras and propaganda around the office really do help you "stay focused and keep shipping", by clearing away your own barriers and resolving debates. The Impact: My first day on the job I submitted a diff that now hundreds of millions of people see every day. Imagining a more connected world keeps me coming in every day, because I know that I'm building that future. The Career Opportunities: There is no arbitrary ladder, no game mechanics, at Facebook. Your career grows as you hack larger things. Because you are encouraged to work across Facebook, jumping teams and technologies, you gain a variety of skills that keeps you agile and flexible. And because Facebook is built on a lot of open source technologies, the skills you gain here are easily transferable everywhere.
Cons
Work / Life balance: If you want to spend most of your time with your family, and work is just a job to you look elsewhere. No one keeps track of your time, but if you want to do well here you'll spend a lot of your free time thinking about the problems you're tackling.
