One of Uber's early employees has teamed up with a high-ranking Facebook engineer for a new, super-stealth startup

A new, stealth startup in Silicon Valley has already raised $8 million from Greylock for its first round of funding, sources close to the company confirmed with Business Insider.

Cofounded by Michael Pao, an early Uber employee, and Jon Perlow, a high-ranking Facebook engineer, the startup is still in its early days, but it's safe bet that it will be working on a new marketplace based on the pedigree of its founding team.

Business Insider first heard that it might have something to do with the on-demand storage space - something that's attracted a lot of attention from investors already - but sources close to the company said it's still too young and new.

Pao had joined Greylock as its entrepreneur-in-residence in January to work with Simon Rothman, one of its partners and a marketplace expert after he built eBay Motors. Rothman has already joined the board of Perlow and Pao's startup, sources close to the company said.

Perlow is a crucial part of the founding team thank to his experience as a high-ranking engineer at Facebook. He'd been at the social network since 2011 after it acquired (and subsequently shut down) his social media company, Beluga. Prior to that, he'd spent over a decade working at both Microsoft and Google.

Pao's expertise comes from the four and a half years he spent at Uber, helping build it into the ride-hailing Goliath it is today. One of his team's early contributions to Uber was surge pricing, an early learning experience in what it takes to build a marketplace.

While some investors have cooled off funding on-demand companies and marketplaces, Pao told Business Insider in January that he's not worried about trying his own hand and building the next one.

"There's never been a better time to start specifically a marketplace," Pao said. "Great companies get started at any time regardless of the macrocycle."