Facebook has just announced that it has hired David Ebersman as its new CFO. Ebersman replaces Gideon Yu, who left the company earlier this year in relatively sudden fashion.

Ebersman is the former EVP and CFO of Genentech, a leading biotech firm recently acquired by Roche, where he had worked for the last 15 years and served as CFO since 2006. He starts at Facebook in September.

“We received a lot of interest in the CFO position and had the opportunity to meet with many impressive candidates,” Facebook CEO Mark Zuckerberg said.  ”We quickly recognized that David was the right person for Facebook.  He was Genentech’s CFO while revenue tripled, and his success in scaling the finance organization of a fast growing company will be important to Facebook.”

“After meeting with Mark and the rest of the team, I was thoroughly impressed with everyone’s drive and sense of purpose to help people connect and share,” said Ebersman.  ”Mark is constantly pushing the company forward and he’s assembled a world-class team that is achieving remarkable results both for its users and as a business.  I’m excited to join this effort and this new industry.”

Ebersman’s hire brings the three month long search process for Yu’s replacement to an end. Yu joined Facebook as CFO in 2007, replacing former CFO Mike Sheridan. At the time, Facebook said it has retained Spencer Stuart to lead its search for a new CFO “with public company experience.” Since then, Facebook raised $200 million from Russian investment firm Digital Sky Technologies, who said it would also buy common stock from employees in the upcoming months.

In addition to building out Facebook’s financial organization, Ebersman (or his successor) will be responsible for managing the company’s efforts to go public, if and when the company does so. Recently, in an exlusive interview with Inside Facebook, Zuckerberg explained why the company shared details of its financial situation publicly earlier this year:

Justin Smith: One of the messages I’ve heard from [Facebook COO] Sheryl Sandberg is that Facebook feels like there is some misconception of its advertising sales success. Why do you think there is a potential misconception there about how things are going?

Mark Zuckerberg: I think that’s partially because there’s been data in the market about companies not doing that well with advertising. We decided earlier this year to issue three new stats: five quarters of EBITDA profitability, 70% growth in revenue year over year, and that we’ll be cash flow positive in 2010 based on our current estimates.

The reason that we did that was because we felt like the general perception around things was that we weren’t anywhere near those levels. You know, thoughts like ‘the economy isn’t doing well, so Facebook isn’t doing well or is losing money,’ when in reality we’re on track to be cash flow positive really soon.

I don’t know how those perceptions got there, but that was why we issued those numbers – to try to clear that up. I think that since then, people’s perception around things seems to mirror reality more. It’s a tough balance as a private company, because the easiest thing would be for us to just go out and tell people what our revenue numbers are, but we don’t want to do that.