Fifty-first Facebook employee Katherine Losse has published a tell-all that details life inside the social network in its first six years.

"The Boy Kings," based on Losse's experience at Facebook between 2005 and 2010, recounts Mark Zuckerberg's leadership quirks, Facebook's privacy foibles, the hierarchies inside the male-dominated office, and the socializing that went on between the architects of the world's biggest social network -- at clubs, concerts, pool houses and online.

"When the meetings ended, he [Mark] would say either 'domination' or 'revolution,' with a joking flourish of a fist, and everyone would laugh, nervously, but with a warm and almost chilling excitement," Losse writes in "The Boy Kings." "It was like we were being given a charter, by a boy younger than most of us, to take over the world and get paid to do it."

You describe Facebook as a fraternity: "It was like Mad Men but real and happening in the current moment as if in repudiation of fifty years of social progress," you write. You recount how, in 2006, all of the women at Facebook were asked to wear T-shirts emblazoned with Mark Zuckerberg's photo -- while the men were exempt. And how one employee consistently propositioned his younger female colleagues for threesomes. How did that environment evolve while you were there? The arrival of Sheryl Sandberg really helped because she was vocal and would say, 'I really care about women in the workplace. I want to make this a good place to work.' I think that was a huge relief for women employees. It was a clear turning point for the company in terms of knowing that these things were serious and needed to stop happening. Without anyone who cares about these issues, there are not going to be consequences. Without someone in charge who could make these issues matter, it was easy for people not to take them seriously.

What was it like to be a woman at Facebook in the early days? There were very few women obviously, and most of the women were not in engineering. Engineering was what the company valued, so that created a natural hierarchy where guys who were engineers weren't really in an environment where they had to worry about how their behavior was perceived. Sometimes being on the engineering floor felt like a pretty testosterone-heavy environment.

What advice do you have for women trying to navigate male-dominated work environments? This is something Sheryl says: You have to believe in yourself. No matter what happens, as long as you think you're contributing and have something to offer, I think the environment you're in is going to reflect that back to you. That's what helped me move up in the company.

What sort of consideration or discussion would go on internally around the cultural repercussions of Facebook's new features or offerings? The launch of frictionless apps, for example, introduced entirely new ways of keeping up with our friends' activities, as did the News Feed and Timeline. Mark always says he wants to create information flow, and those types of new technologies are just the latest outcome of that. I can't actually say I heard people talk about the user side of it –- like how does this change the life of the person who starts using these technologies. It's a very systems-based approach -- thinking about the social network as a global system in which information is flowing quickly. That's different from the user's way of thinking, 'How does this affect me personally and my individual life?' Facebook has to take the global approach.

Who's number one at Facebook -- Advertisers? Users? Investors? Facebook itself? Who does Facebook believe it's answering to? There's the sense that you optimize the system, Facebook, in order to optimize for the user: If we make a system where information flows efficiently, that will make each user's experience better. But in order to do that, each user can't really limit or particularize their own experience of the site. There's the idea that if we make the system more efficient, that will ultimately benefit the user, even if the user wants to do something different.

In your book you mention that Facebook at one point had a "master password" anyone could use to access a user's profile -- personal messages and all -- a revelation that wasn't entirely reassuring from a privacy standpoint. You also point out that third-party developers were "technically" supposed to scrub user data every 24 hours, but if they didn't, Facebook "had no way of knowing." Should we trust Facebook? We're putting so much information online and providing so much of our lives to these websites. Can you trust any entity that's not you to always act in your interest? We have to ask that question of every organization and website that we're interacting with. The question isn't so much about trusting one particular site, but rather what is our relationship to the Internet, and to these machines that can easily gather information? Is there some limit we want to place on that, or are we just going to hope that it's all going to be fine?

What do you see as Facebook's Achilles' heel, based on your time there? Facebook wants to bring people along into this world where sharing is lubricated and is easy. Everyone, to some extent, wants to do that and have that option open to them. But the question for Facebook is always going to be: Is there ever a point where people say, ‘No, this is too far, too much'? And I think figuring out where that line is is what I'd be thinking about if I was running Facebook.

What motivates Mark? I don't think money is very interesting to him. What's important to him is having the culture he wants at Facebook, the type of site he wants, and continually being able to grow. That's hard as the company gets bigger ... but he wants the same kind of freedom and flexibility and growth potential that Facebook has had from the beginning.

This interview has been condensed and edited for clarity and length.