Gilles Mischler built and designed Facebook's IT infrastructure from the ground up.
Employed by Facebook from: June 2005 - May 2010
Position at Facebook: SiteOps Engineer
Where he is now: After Facebook, Mischler went to Playdom. He was only there for a few weeks when the company was acquired by Disney for more than $700 million. Mischler then went to Nokia as a network engineer, and had a stint as a consultant for fast-growing companies. For the past year, he's been a network engineer at Dropbox.
You can thank engineer Scott Marlette for being able to visually stalk all of your friends. He created Facebook's photo application.
Employed by Facebook from: June 2005 - January 2010
Position at Facebook: Engineer, Product Manager
Where he is now: Marlette went on to co-found GoodRx and advise a startup, ProperFlow.
Dan Neff had a short, five-month stint as one of Facebook's first employees and was responsible for rolling out new site features.
Employed by Facebook from: May 2005 - October 2005
Position at Facebook: Build/Release Engineer
Where he is now: Operations Architect at Adobe Systems, per his LinkedIn page.
Aaron Sittig was brought on by Sean Parker. He created the concept of tagging friends in Facebook pictures and "liking" posts.
Employed by Facebook from: May 2005 - December 2o12
Position at Facebook: Design Strategy Lead
Where he is now: Sittig left Facebook in December 2012. He's close friends with Mark Zuckerberg, who attended his wedding in 2011. Sittig hasn't updated his LinkedIn profile since he left Facebook.
Naomi Gleit was tasked with making sure "literally everyone in the world was on the site."
Employed by Facebook from: April 2005 – Present
Position at Facebook: Marketing Associate
Where she is now: Director of Product for Growth and Engagement at Facebook. Gleit told Lean In how she landed the early job at Facebook soon after she graduated from Stanford University (hint: by leaning in).
Nick Heyman was in charge of handling Facebook's explosive traffic, although he wasn't there for very long.
Employed by Facebook from: April 2005
Position at Facebook: Director of Operations
Where he is now: Heyman worked at Friendster, Facebook and then Twitter. Now he's an investor in startups such as PandaWhale and ShopPad.
Steve King directed Facebook's media sales and was responsible for getting the first big advertisers on board like Panasonic and Microsoft.
Employed by Facebook from: April 2005 - July 2006
Position at Facebook: Director, Media Sales
Where he is now: After Facebook, King joined LocaModa as its VP of Sales. Now he's a general partner at Second & Fourth, a group of seed investors in Boston.
Tricia Black worked at Y2M, a firm that sold ads for college magazines. Eduardo Saverin set up a meeting with Black, who began selling ads for Facebook and eventually became the first VP of Sales.
Employed by Facebook from: March 2005 - June 2006
Position at Facebook: VP, Advertising Sales
What she's doing now: Black has been self-employed since she left Facebook, per her LinkedIn page.
Steve Chen left Facebook after a few short months to start YouTube.
Employed by Facebook: For a few months in 2005
Position at Facebook: Senior Software Engineer
Where he is now: Chen went on to co-found YouTube, which he sold to Google for $1 billion. He co-founded another company, AVOS, in 2011. In 2014, Chen joined Google Ventures as an entrepreneur in residence.
Next to Zuckerberg, Kevin Colleran has been the longest-serving Facebook employee. He lived with Zuckerberg in the 2004 Palo Alto summer sublet.
Employed by Facebook from: April 2005 – July 2011
Position at Facebook: Global Partnerships
Where he is now: Colleran was one of the last initial employees to leave Facebook. Now he's a startup investor at General Catalyst and a Managing Partner at Slow Ventures.
Matt Cohler was brought on by Peter Thiel and was formerly one of the founding members of LinkedIn.
Employed by Facebook from: February 2005 - October 2008
Position at Facebook: VP Product Management
Where he is now: Cohler is a general partner at Benchmark Capital and serves on a number of startup boards, including Asana, Couchsurfing, Quora and formerly Instagram. He was also an early member of LinkedIn.
Ezra Callahan had been roommates with Sean Parker and was hired to "whittle away" at Eduardo Saverin's CFO responsibilities.
Employed by Facebook from: December 2004 - July 2010
Position at Facebook: Manager of Internal Communications, Product Manager
Where he is now: According to his LinkedIn page, Callahan is living in the Los Angeles area. He hasn't listed any new jobs since his Facebook employment. But a few years ago, he decided to invest in a Palm Springs hotel after he noticed millennials flocking there. The Examiner wrote about his plans then: "[Callahan] and his architect Chris Pardo unveiled their plans for a hip, new hotel and restaurant at 1551 N. Palm Canyon, between Vista Chino and Stevens. Their 32-room contemporary hotel, called 'ARRIVE,' is significant because it will anchor the north end of the Uptown Design District – itself a major hit that has seen one restaurant and retailer after another splash new life onto the Desert scene."
James Pereira was Facebook's 7th employee. He left three years later.
Employed by Facebook from: July 2004 - August 2007
Position at Facebook: Engineer
Where he is now: Pereira now lives in Portland, Ore., according to his Facebook page. It's not clear what he does for work.
Sean Parker was an early employee at Napster and was founding president of Facebook.
Employed by Facebook from: June 2004 - January 2006
Position at Facebook: President
Where he is now: Parker tried to create a new buzzy video startup, Airtime, but it flopped. Last summer, he infamously got married in an extravagant outdoor affair. Now he's a managing partner of Founder's Fund. He's also heavily involved in Spotify as a board member, one of many startups he's invested in.
Taner Halicioglu was Facebook's first "real" employee outside of the founders. He built out the entire initial hardware infrastructure.
Employed by Facebook from: October 2004 - November 2009
Position at Facebook: Senior Software/Operations Engineer
Where he is now: Halicioglu became the Lead Reliability Engineer of Battle.net at Blizzard Entertainment. Now he is a lecturer at UC San Diego in the school's Computer Science and Engineering department.
Eduardo Saverin was a Facebook co-founder and its first CFO. He famously sued Mark Zuckerberg and the two reached a settlement.
Employed by Facebook from: February 2004
Position at Facebook: Co-founder
Where he is now: After winning a legal battle with Facebook which let him retain his co-founder status, Saverin began angel investing in startups like Qwiki and Chris Hughes' Jumo. In 2011, Saverin (who was born in Brazil) renounced his U.S. citizenship and went to Singapore, likely because of the taxes he'd have to pay following Facebook's public offering. He says he has no hard feelings when it comes to Facebook or Mark Zuckerberg, who ousted him from the company shortly after its launch. Since then, Saverin has invested in startups like the eggless mayonnaise company Hampton Creek.
Chris Hughes co-founded Facebook and served as the site's spokesman. He later coordinated all social networking aspects of Obama's 2008 campaign.
Employed by Facebook from: February 2004
Position at Facebook: Co-founder
Where he is now: After leaving Facebook, Hughes went on to co-found Jumo, a startup that tries to utilize social media to change the world. He is also an investor in UpWorthy, a viral news startup. His husband, Sean Eldridge, is interested in politics and in earning a congressional seat. The pair bought a multimillion-dollar home in the Hudson Valley, possibly with the hope of moving Eldridge's political career forward. In 2012, Hughes bought the majority stake in the magazine The New Republic. He's now the Executive Chairman and publisher of the publication.
Andrew McCollum designed Facebook's first logo and worked on a side project with Zuckerberg, Wirehog.
Employed by Facebook from: February 2004 - September 2006
Position at Facebook: Engineer, Co-founder
Where he is now: McCollum joined Flybridge Capital Partners as an entrepreneur in residence in 2011. Then he became one at VC firm NEA. Now he's invested and involved in other tech startups, such as Quilt and JobSpice.
Dustin Moskovitz, Facebook's first CTO, was Mark Zuckerberg's roommate. The two dropped out of Harvard together to move to California and work on Facebook.
Employed by Facebook from: February 2004 - November 2009
Position at Facebook: Co-founder
Where he is now: Moskovitz cofounded a startup called Asana in 2008 with a Facebook engineering manager named Justin Rosenstein. He's also an investor in tech startups such as Path, Venmo, Flipboard and NationBuilder.
Mark Zuckerberg founded Facebook. The blue design of the site is partially because of his red-green color blindness.
Employed by Facebook from: February 2004 - Present
Position at Facebook: CEO and co-founder
Where he is now: He's still at Facebook — but now he's much richer. His net worth is $34 billion.
BONUS: Adam D'Angelo was high school friends with Mark Zuckerberg and eventually left Facebook to found Quora.
Employed by Facebook from: November 2006 - June 2008. Although he technically wasn't one of the first 20 employees, D'Angleo was one of Zuckerberg's best high school friends and worked on the social network site long before he was on the payroll.
Position at Facebook: CTO
Where he is now: Co-founder and CEO of Quora.