FORTUNE — For engineers hoping to land a job at Facebook, here’s the good news: Facebook is not Google. You don’t need a computer science degree from Stanford or Carnegie Mellon. You don’t need a Ph.D. You don’t need a quasi-perfect GPA, and you may not have to chase copies of your SAT transcript. After all, Facebook was started by a college dropout with a passion for hacking, not by a pair of doctoral students working on the seemingly intractable problem of finding relevance in a sea of Web pages.

Now here is the bad news: none of that means joining Facebook’s engineering ranks is easy.

As the company has grown, and Mark Zuckerberg has moved from coder to curator, he has needed a never-ending supply of engineers who are not only smart programmers but also embrace Facebook’s hacker ethos. Many have come through the company’s vast recruiting operation, which has reached well beyond the top schools. “I’d rather have the top student out of U.T. or University of Central Florida than the 30th best from Stanford,” says Jocelyn Goldfein, an engineering director. To reach students in schools where it cannot send interviewers, Facebook has set up online programming puzzles that students can try to solve in hopes of getting noticed.

EXCLUSIVE: Inside Facebook

Those lucky enough to make the first cut should be prepared to show their hacker chops: the first interview will involve coding, not brainteasers first popularized by Microsoft (MSFT) in the 1990s. “There’s no hand-waving your way through a coding interview,” Goldfein says. “So it’s just sort of a great first litmus test that we’re dealing with someone serious.”

Those who pass that test will get invited to Facebook proper for a series of four tightly scripted interviews where, no surprise, more coding will be expected. Indeed, two of the interviews are purely programming exercises, says Goldfein. The other two will depend on the expertise of a candidate, but they will involve “solving hard problems” and “engaging on a technical level,” she says. In at least one of the interviews, Facebook will be taking a “behavioral” look at how candidates tackle a problem, how they break it down, how they ask for help.

Unlike Google (GOOG), where CEO Larry Page still reviews every offer, Zuckerberg is not typically involved in approving most hires. But detailed reports from the interviews go up to a hiring review committee of Facebook’s top technologists. “The most common reason for us to pass on a candidate is that they just are not up to the technical bar,” Goldfein says.

MORE: The story behind “Inside Facebook”

There is, however, a way to bypass this whole process: start a company that gets noticed by Zuck or his top managers for its product, its speed and, of course, its own hacker ethos. Over the years, Facebook has acquired more than 28 companies largely for their engineers. In most cases, it killed the startups’ products. Silicon Valley has a name for this peculiar twist on the traditional M&A: the acq-hire, or talent acquisition.

While Facebook didn’t invent this costly recruiting practice, it has institutionalized it more than any other company. And some of its talent acquisitions have produced hires that became Zuckerberg’s closest deputies. Indeed, two of Zuckerberg’s five direct reports who oversee key product areas joined Facebook when their companies were acquired: Bret Taylor, a Google veteran and co-founder of the social aggregator FriendFeed, and Sam Lessin, a buddy of Zuckerber’s from the Harvard days who founded Drop.io, a file-sharing service. In a 2010 interview, Zuckerberg said this approach to recruiting top entrepreneurial — read hacker-friendly — talent was well worth the price.“Someone who is exceptional in their role is not just a little better than someone who is pretty good,” he said. “They are 100 times better.”

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