Pros
I just left Google and joined Facebook, and felt so much happier. The reasons are:
1. The real impact
At Google I joined a team whose product is only used by less than 1000 people, and even for that product I was assigned to do a peripheral part, whose functionality actually doesn't matter at all. Just for that module, I had to write unit test for every silly part of the code, and took long iteration cycles. I admit those are good engineering coding trainings, however taking precious time in my life to work on something that doesn't matter is just a waste of my life.
In Facebook things just move so much faster. There are standard software engineering review process but not as rigid. Just during training (boot camp) weeks, I had tasks to change very important part of Facebook's core code, and the second day after I check-in my code, it got shipped to almost 1 billion people. As a software engineer I cannot recall a moment I felt better for my job.
Then I joined a team that's extremely important to Facebook's revenue. A mistake in the code I changed could cause Facebook million dollar a day. However Facebook just trusted us, allowed us making mistake and having quick iteration cycles to test ideas fast. If I make a coding mistake in my team in Google it might cost Google nothing in terms of revenue as my product was small, however the development process was so strict I could not have chance to try my innovations or test my ideas. But in Facebook that's all possible.
2. The organizational structure
Google's organization is now very structured and hierarchical. Facebook is having more layers, but the working style is still flat, and social-network style. Speaking to people in different teams, form an idea, lead a virtual team and complete it, this style is still valued. My boss is more like a mentor helping me navigating through the ideas, rather than an authority telling me what to do.
Cons
1. I don't quite like the office decoration style. A little bit stressful and factory like.
2. The compensation is better than Google but not as good as other smaller companies.
3. Despite good acquisitions for solidify the position in social media, social networks, there is still uncertainty about the future of this company.
