There's outsized attention this year on Uber, the super-fast-growing global purveyor of "classy rides" and surge pricing, and the company's CEO is boasting of the head-count explosion he's anticipating for 2014.

"We have 550 employees. That's approximate," Travis Kalanick, the co-founder and CEO of Uber told the Wall Street JournalBy the end of 2014, he said: "We're definitely going to be well over 1,000, maybe in the 1,500-to-2,000 range." 

Those numbers--hiring between 450 and 1,450 employees--certainly make for a wide range. But they're completely plausible: Just look at the company's impressive growth rate and current jobs board for evidence. And should Uber find itself on the upper end of that range, that amounts to a quite remarkable hiring spree. It would, for instance, land the company very near the top of Inc.'s rankings of top-hiring companies in the U.S., the Hire Power Awards.

Bringing on more than one employee a day would be a tall order for any company. And for Uber, where employees are spread across 60 cities, it might be mammoth--if not for an innovative hiring strategy the company's founders and early employees designed from the ground up. It involves a little bit of pop psychology, a super-simple org chart, and job-position-specific tests.

When I interviewed Kalanick last year, he explained to me a little about Uber's unique hiring process. He says early on in the company's life, more than three years ago, he and his co-founder, Garrett Camp, realized there was no existing archetype for the sorts of employees he was seeking. Nor were there uniform qualifications for such jobs.

"We couldn't say, 'I'm looking to hire a general manager for a logistics business with a consumer-facing brand that's disrupting the taxi industry,'" Kalanick said. In short, no one had ever held such a job before--and this was just one unique position Uber was looking to fill. "Where do you go to find that guy or girl?"

For employee No. 1, Kalanick turned to Twitter. "Looking 4 entrepreneurial product mgr/biz-dev killer 4 a location based service.. pre-launch, BIG equity, big peeps involved--ANY TIPS??" A young Chicagoan in a GE management-training program named Ryan Graves tweeted back: "here's a tip. email me :)"

Graves became Uber's business manager in San Francisco, and launched operations in the city in May of 2010. From that point, Uber's hiring processes grew to be a great deal more deliberate. Today they involve a traditional online-application process, pre-screening by a human-resources department, and interviews with managers. Pretty normal. But they also involve job-specific tests of an applicant's ability to think-on-the-fly and perform the specific job they're seeking.

Positions at Uber general fall into one of a few buckets. The smaller buckets include technologists (web developers, programmers, rocket scientists, and similar roles), who build the back-end product, app, and work on innovation. Most are based in San Francisco, as is upper management, a legal team, designers, and, most recently, a human-resources department called "people operations."

But the bulk of Uber employees are spread out in cities around the globe. In each city team, a general manager oversees a group of employees that's split into two branches: Operations and Community. Operations is responsible for overseeing logistics, and is particularly focused on the driver side of Uber's operations. Community is responsible for supporting customers, meaning the riders who hail Uber-operated vehicles.

The difference between individuals who are good candidates for operations jobs and those who fit in community positions is clean in design, but requires a little armchair psychology. Community managers "are all right brained," Kalanick says. "D-ops (Uber's slang for "driver operations") are left-brained. They are crunching numbers all day."

Who makes a good driver-operations manager?

"They have to pass an analytics test," Kalanick says, noting that highly motivated Wall Street banking types often do best in the role. "They are lots of former Goldman people."

Community managers are more social, more media-minded--the type of individual who on their personal time uses Twitter, Instagram, and Facebook. You know, for fun.

According to Kalanick, an applicant for a community manager position takes a "creativity test" rather than an analytics one. When I asked him whether that entailed writing a sample blog post for the company, or writing a launch-party invite, or doing social media, he demurred on specifics, perhaps not wanting to disclose Uber's HR secret sauce. "Something like that," he said.

The guy or gal in charge in a given city, the general manager, oversees both operations and community. He or she needs to be adept at both number-crunching and community support--both right-brained and left-brained. " We've gotten really good at finding that creative and analytics cross with a leadership component," Kalanick says. "In 15 years all of these guys will be running Fortune 500 companies. They are killers."

General managers take both an analytics test and a creative test--plus they must submit a six-month development plan for their city. Uber declined interview requests with general managers for this article.

Outside observers, including scholars and CEOs behind fast-growth companies I've spoken with, universally suggest that Uber is wise to be beefing up its internal human-resources department as it prepares for massive growth in head-count.

Yodle, a company that sells local online advertising and marketing to mostly small business, is familiar with Uber-sized growth: It added 756 people to its company in the past three years. Today, the company employs just short of 1,300 people across five cities: Atlanta, Austin, Charlotte, New York City and Phoenix.

The company's founder and CEO, Court Cunningham, says Yodle's hiring strategy has been successful thanks in part to two decisions he and his executive team made years ago. The first: hiring an executive recruiter while creating and scaling a human-resources department to manage the company's growth.

"People thought it was a crazy move on our parts," Cunningham says. "Making that investment seems obvious now, but it's amazing how many companies I talk to who don't do it. They instead end up paying a fortune for recruiters."

The second pivotal decision was to set a fairly rigid process for hiring, in which the same management teams interview every candidate for their department. "The hiring teams all ask the same sets of questions, and it's a specific set of people, doing it in high volume, means that they get better at it over time," Cunningham says.

Paul Osterman, a professor of human resources and management at the M.I.T. Sloan School of Management, suggests that the U.S. labor market is ripe for hiring low-level employees. But for more highly-skilled workers, companies such as Uber should "be more willing that most firms to ramp up their internal training."

Cunningham encourages other fast-growth companies looking to rapidly ramp up head-count to turn their attention away from specific numbers they're targeting. 

"The goal is to hire the best people you can get--not hit the numbers you want," he says. "If you lower the bar on talent, or don't put in the time post-hire to do the culture assimilation, you risk creating a Frankenstein of people who come from all these different companies, and who don't embody your own company's culture."