By Lydia DePillis, CNN Business

(CNN) -- When Amazon arrives in the northern Virginia suburb of Crystal City, eventually bringing 25,000 jobs as part of its vaunted headquarters expansion, the tech behemoth will quickly become one of the region's biggest employers.

It will be as big as the Pentagon, where about 26,000 people work. It would almost match the District of Columbia's local government payroll. It would be more than double the staff of the House and the Senate combined.

And finding all those people? That's going to be a challenge.

The DC-area unemployment rate is 3.3%, well below the national average — but that likely masks the even lower availability of the types of professionals Amazon will be looking for.

The Seattle-based behemoth announced Tuesday that it will expand to both Crystal City and the New York neighborhood of Long Island City, splitting the 50,000 jobs it had originally said would go to a single second headquarters.

In its request for proposals from prospective host cities, Amazon said that the positions at its new headquarters will include executives and managers, software development engineers, lawyers, accountants, and administrators. Tuesday's announcement said they will have an average salary of at least $150,000 a year.

While Amazon will certainly recruit from outside the area, people who already live in the Washington area would be easy targets, especially since the company will simultaneously be trying to recruit 25,000 people for its other new headquarters location in New York.

"It's a name that you want to work for. It's a name that everybody knows," says Chris Vennitti, president of the Reston, Virginia-based recruiting and staffing firm HireStrategy. "This area has never seen anything on the size and scale of an Amazon coming to our area and pulling from other companies."

Employers are already under pressure to attract and retain talent given the booming economy in the area.

The consulting giant Booz Allen Hamilton, for example, has hired 780 net new people over just the past quarter. In its recruiting materials, it emphasizes how its employees make an impact, collaborate with diverse colleagues, and stay on the leading edge of technology — all things that young workers say they care about. In 2016, Booz's DC office opened an "Innovation Center" to host teams that work on projects including cybersecurity, data analytics, and healthcare IT.

"We are very much holding our own in the current environment and expect that will continue," says Betty Thompson, Booz Allen's senior vice president for people services. "We are not afraid of the competition."

Although not as flashy as Silicon Valley or Seattle, Northern Virginia has a long lineage of technology entrepreneurship, thanks in part to research performed at places like the Defense Advanced Research Projects Agency, widely known by its acronym DARPA, as well as access to institutional clients like trade associations and government agencies.

America Online spent its formative years in an office park in what would become Tysons Corner, about halfway between downtown Washington and Dulles Airport in northern Virginia. Nextel, a wireless service provider that later merged with sprint, was born in Reston, a planned community near Dulles.

In an Instagram post about the Amazon news, AOL founder Steve Case said it was "fitting" that Northern Virginia will host the tech giant's new headquarters because of the region's role in advancing the growth of the internet. "It has been great to see how the tech sector has evolved in VA over the past 35 years," he said.

In recent years, the region has tried to foster a buzzier tech scene, and now boasts successful home-grown companies like the educational technology provider EverFi as well as startup accelerators like the cybersecurity-focused Mach37, which is funded by the state of Virginia.

That effort has been plagued by high-profile failures like LivingSocial, the daily deals company that expanded and contracted like a supernova before being bought by Groupon in 2016, and attrition by companies that have left to chase venture capital in San Francisco, Boston, and New York.

Washington's population growth among people aged 20 to 34 has slowed in recent years, according to Census estimates. Northern Virginia Technology Council president Bobbie Kilberg says that despite the area's hot job market, young workers have been repelled by the rising cost of housing and transportation.

She hopes that Amazon will give them a better reason to come and settle. Even though Amazon's DC office will focus heavily on government, the company's overall profile is consumer-facing and omni-present.

"I think that Amazon will provide them with something exciting that they find very attractive," Kilberg says. "So I think people will start reversing the out-migration and make it an in-migration."

Big government consultants and contractors have also found that their best weapon in broadening the pipeline of candidates is cooperation. Northern Virginia's tech companies are working collectively to align local educational institutions' curricula with the skills needs of large employers, and to promote careers in computer science and engineering. They've also started accepting candidates with more specific vocational degrees, rather than full four-year bachelors' degrees, and have expanded their apprenticeship programs.

One of the leaders on that front has been Amazon itself: The company's cloud services division, which already has a large public sector office based in the Northern Virginia suburb of Herndon, has been one of the most active in employing apprentices after putting them through an intensive 6-month training program.

"They get that it has to be an industry-wide solution," says Steve Partridge, vice president of workforce development at Northern Virginia Community College. "It can't be that one company implements something and sucks up all the talent."

Even younger companies, which don't have the bandwidth to create training programs or the name recognition to woo people from hotter tech hubs, think Amazon might help with recruiting. Moving to a place with a large employer in your field lowers the risk of taking a job in a new city. If it doesn't work out, you can always walk across the street.

Kestrel Linder is the founder and CEO of GiveCampus, a DC-based startup that sells alumni fundraising software to universities. He has 24 employees and plans to scale up to 100 over the next year, and thinks Amazon coming to the region would make that task a lot easier.

"If you're a sought-after tech worker, when you think about moving to DC, as excited as you might be about working for the tech company that's offering you in a position, at the same time you wonder, 'What about 5 years from now, what's going to be there?'" Linder says. "It would really change what I've been referring to as the opportunity profile of Washington DC."