What do you do when you’re the 32-year-old CEO of a $10 billion company and need advice on how to further grow it? Turn to a 31-year-old fellow CEO of a $250 billion company for advice. That's what Dropbox CEO Drew Houston does, as he told Bloomberg's Emily Chang in an interview that he reaches out to Facebook CEO Mark Zuckerberg when he has questions about scaling his company. Here's how he describes it: "[Zuckerberg’s] given me a lot of advice just on company scaling, how do you organize people, how do you set up these systems. At scale, you have to be a lot more thoughtful about, how do you compensate people, how do you think about mundane things like their titles or how people advance, how do you decide where to place bets, because you have early stage things, you have more mature products, you have this whole portfolio, how do you keep that running, when the challenges are so different at either end of the spectrum. It’s a lot of things like that." Dropbox, founded in 2007, is one of the fastest growing tech startups ever. It just announced it has 400 million registered users and 100,000 paying business customers. Over the past 18 months, its total employees went from approximately 500 to 1,200. When you're growing at that kind of breakneck speed, it's only natural to ask someone who's done something similar before. Zuckerberg's Facebook now has roughly 1.4 billion monthly active users, more than 3X of what it had in 2010. Plus, Dropbox is reportedly having trouble internally to build up a more stable business model and revenue stream, which is causing a lot of question marks around its lofty valuation number. Facebook, on the other hand, had one of the biggest IPOs ever in 2012 and now has over $12 billion in revenue. Houston and Zuckerberg's friendship has been well-documented in the past. In fact, Houston is reported to have a great group of friends and mentors around him who are helping him turn Dropbox into one of the most valuable pre-IPO companies in Silicon Valley. Some of those mentors include Salesforce CEO Marc Benioff and Uber CEO Travis Kalanick, as well as former Motorola CEO Dennis Woodside

What do you do when you’re the 32-year-old CEO of a $10 billion company and need advice on how to further grow it?

Turn to a 31-year-old fellow CEO of a $250 billion company for advice.

That's what Dropbox CEO Drew Houston does, as he told Bloomberg's Emily Chang in an interview that he reaches out to Facebook CEO Mark Zuckerberg when he has questions about scaling his company.

Here's how he describes it:

"[Zuckerberg’s] given me a lot of advice just on company scaling, how do you organize people, how do you set up these systems.

At scale, you have to be a lot more thoughtful about, how do you compensate people, how do you think about mundane things like their titles or how people advance, how do you decide where to place bets,
because you have early stage things, you have more mature products, you have this whole portfolio, how do you keep that running, when the challenges are so different at either end of the spectrum. It’s a lot of things like that."

Dropbox, founded in 2007, is one of the fastest growing tech startups ever. It just announced it has 400 million registered users and 100,000 paying business customers. Over the past 18 months, its total employees went from approximately 500 to 1,200.

When you're growing at that kind of breakneck speed, it's only natural to ask someone who's done something similar before. Zuckerberg's Facebook now has roughly 1.4 billion monthly active users, more than 3X of what it had in 2010.

Plus, Dropbox is reportedly having trouble internally to build up a more stable business model and revenue stream, which is causing a lot of question marks around its lofty valuation number. Facebook, on the other hand, had one of the biggest IPOs ever in 2012 and now has over $12 billion in revenue.

Houston and Zuckerberg's friendship has been well-documented in the past. In fact, Houston is reported to have a great group of friends and mentors around him who are helping him turn Dropbox into one of the most valuable pre-IPO companies in Silicon Valley.

Some of those mentors include Salesforce CEO Marc Benioff and Uber CEO Travis Kalanick, as well as former Motorola CEO Dennis Woodside