Editor's Note: This story, published in early February, profiles Facebook CFO David Ebersman. By all accounts, Ebersman's latest coup is managing the entire IPO process, from calling the shots on how the banks would get paid to running a roadshow that appears to have increased demand, and hence, price.
FORTUNE -- Shortly after he helped to close the $46 billion deal that turned Roche Holdings into the full owner of Genentech in 2009, David Ebersman, who was chief financial officer of the biotechnology giant and something of a protégé to Chairman Art Levinson, started fielding recruiting calls from some of America's biggest companies.
But Ebersman decided to join a startup with fewer than 1,000 employees, meager revenues and a history of cycling through CFOs
The gambit paid off, to say the least.
As chief financial officer of Facebook, Ebersman, who is 42, has been one of the chief drivers behind the company's blockbuster IPO filing.
A quiet and unassuming executive, Ebersman had a stellar, 15-year career at Genentech (rhhby). He joined in 1994 as a business development analyst. He caught the eye of Levinson, who was CEO at the time (he would later join the Apple (aapl) board and become its chairman). Levinson tells me he placed Ebersman on special track in which promising executives were promoted and given new challenges every two or three years.
Within a few years, Ebersman was running product development. After proving his skills as an operator, he was promoted to head Genentech's manufacturing, a position that gave him oversight of about half of the company's 8,000 or so employees at the time.
In 2006, he was named executive vice president and CFO, and earned a reputation for reinforcing long-term thinking. For example he helped push the company to embrace certain costly clinical trials whose results were uncertain but whose potentially payoffs were huge. "These decisions can be the wisest you can make, but if you are looking at the next quarter or at the next year, they are hard to swallow," says Levinson.
As CFO, Ebersman quickly earned the respect an admiration of investors and analysts. "A lot of people, myself included, said 'what the hell is going on at Genentech that they are naming a 34-year-old as CFO," says Mark Schoenebaum, a senior analyst covering biotechnology and pharmaceutical companies at the ISI Group. (Ebersman was actually 36 at the time.) But Schoenebaum says that at their first face-to-face meeting he was quickly mollified. "He comes in, and within 30 seconds of his opening his mouth, I said, 'I get it.' He comes across as brilliant."
Schoenebaum says Ebersman was well liked on Wall Street, in part because of his willingness to deal forthrightly with investors' questions. "He is a very nice guy with not a shred of ego," he says. And he says Ebersman played an important role in helping to get the most value for Genentech shareholders during delicate takeover negotiations with Roche.
For all his success at Genentech, at Facebook he was confronted with a radically different world: a freewheeling startup, where 20-something engineers with an inherent mistrust of "suits" ruled the roost.
Ebersman worked hard to learn the business and to fit in. A detail-oriented person who likes to see things for himself, Ebersman spent hours drilling down on Facebook's advertising business, and becoming familiar with the costly, electricity-guzzling infrastructure. After the company decided to go forward with its biggest capital project ever, a giant state-of-the-art data center in central Oregon, he visited multiple times during construction to keep tabs on its progress.
Fitting into Facebook's culture also took some stepping out of what you'd think of as the comfort zone of most finance professionals. Early on, Ebersman led a finance department "hack-a-thon," modeled after the all-night programming sessions that are common among Facebook's engineers.
The result: a multi-year budget that was "hacked" overnight by a still-small team of finance whizzes. It was more exercise in team-building than actual financial plan. "It still took months to finalize it," Ebersman told me in a rare 2010 interview. "It was meant to be a nice tie in with the culture."
Ebersman earned additional credibility with the Facebook troops through an extracurricular activity: He joined Feedbomb, Facebook's in-house top-40 cover band, as its bass player. The band has played at Facebook's 7th birthday party and a number of venues in Palo Alto and San Francisco. (In a band photo on Facebook, Ebersman traded his usual buttoned-down shirt for a Guns and Roses t-shirt.) "Musicians have a lot of respect among engineers," says a veteran of Facebook. "It gave him a fair amount of cred."
Ebersman's strong operational background provides an extra layer of comfort for Facebook and its would-be public investors.
The post-Facebook aspirations of Sheryl Sandberg, the company's high-profile COO, have long been the talk of Silicon Valley. No one expects her to leave any time soon. But if Sandberg opts for a future in politics or public service down the line, Facebook would have in Ebersman a well-prepared executive to step into her shoes. Says Levinson: "There are very few jobs he wouldn't excel at."