I have found a couple of extremely inspiring fragments from an interview with Mark Zuckerberg (via ☞ Business Insider ) on which are covered subjects like: how is Facebook environment different from Google (by being focused, quick and bold), getting user feedback the Facebook style, what means to be quick nowadays, etc.

[…] combined with boldness to try new things. Our goal is to move fast and the other half of our mission is to break stuff. We have a willingness to try stuff out and see what happens even on the system side where engineering is difficult.
— Mike Schroepfer, VP of Engineering
Our core values are about moving fast. That is the ability to innovate and iterate as fast as possible. You never know what you got is the right {product} so it’s really important to get it out in the market and test it with people to see what they think. It’s not about what they say, but also how they use it. The question is “do they use it, do they enjoy it, do they come back to the site, and do they engage it?”
— Mike Schroepfer, VP of Engineering
And here is the whole ☞ interview with Mark recorded by Business Insider