TECHNOLOGY

Five years ago, Toptal, a self-described freelance network, had 25 programmers on its rolls and about the same number of clients. Today it represents thousands of coders (it won't specify how many) and has more than 2,000 clients including Airbnb, Pfizer and J.PMorgan. Rival agency 10x Management said the average budget for software-writing contracts has doubled in the past three years as the company attracts bigger and broader projects.

Toptal, a virtual company with no home base, accepted fewer than 3 percent of the 15,000 applications it received in the past two months, said Taso Du Val, co-founder and chief executive officer. The vetting process has four parts: an interview to screen for personality, a technical exam, a live coding test and a test project to evaluate the candidate in a realworld scenario.

Helder Silva, a software engineer from Portugal who has worked at Deloitte and other companies, passed the first two rounds but failed the live coding exam because he took too long to solve one problem. "You miss something and you get kicked," Silva says. "I get where they are coming from. They charge a large amount to their customers and they expect you to be as proficient as you can get."

With the tagline "genius on demand," 10x Management typically represents about 100 software developers; the New York-based agency receives thousands of applications every year.

Martin Langhoff, 39, typifies the elite freelance coder. Having taught himself programming at age 9, Langhoff went on to become chief technology officer at the non-profit One Laptop Per Child program, where he managed a software and hardware team, industrial design, manufacturing and prototypes. Burned out and wanting to spend more time with his son, he joined 10x.

Langhoff sometimes can be found writing code aboard Persuasion, a 41-foot timeshare sailboat; he bartered access to the Jeanneau 409 by writing the timeshare booking software. Most recently Langhoff helped build a security product for a "major U.S. corporation," he said, a project that typically would take three years to complete. The 10x team took three months.

"We get called to do mission-critical things that will make or lose the company a lot of money," said Langhoff, of Fort Lauderdale, Fla.

Chris Goodney/Bloomberg "There's definitely a level of stress that comes with being independent that's absent at Google, but I like that," says freelance coder James Knight, a former Google employee, shown on a rooftop in Brooklyn this month.