Jan Koum
Jan Koum LinkedIn

Facebook CEO Mark Zuckerberg might have known Jan Koum “for a long time” but not many others are familiar with him. Koum and Brian Acton founded the mobile-messaging app WhatsApp that grabbed the headlines on Wednesday after Facebook announced it would buy the messaging system for $19 billion.

“I’ve also known Jan for a long time, and I know that we both share the vision of making the world more open and connected,” Zuckerberg wrote on his Facebook page after the company bought the messaging system that has 450 million users. “I’m particularly happy that Jan has agreed to join the Facebook board and partner with me to shape Facebook’s future as well as WhatsApp’s.”

Koum is now a Facebook board member, Forbes.com wrote, but his LinkedIn profile doesn’t mention that, at least for now. On LinkedIn, the 37-year-old says he is a QA tester and a senior tweet manager, and he requests people check out Acton’s page if they want to know more about what he does.

Koum was employed at Yahoo for nearly a decade, where he worked in infrastructure and security engineering. He said on his LinkedIn page that he barely graduated from High School and that he dropped out of San Jose State University.

Koum doesn’t seem to be a man of many words, or one to brag, but he's certainly in the spotlight now that social media giant Facebook has bought his app, which was already a huge product in Europe.

Not surprisingly, his Twitter account is also vague. He has only written 48 tweets and only follows one account. After Wednesday’s Facebook announcement, however, he’s gained a total of 10,000+ followers.

Koum and Acton aren’t the first “messaging” entrepreneurs to be pelted into the realm of 10-figure fortunes. Forbes.com wrote that Lee Hae-jin, the founder and head of Korea Internet portal operator Naver Corp., became a billionaire after Line, Naver's instant-messaging application, hit it big. Line is one of WhatsApp's biggest competitors and provides services mostly in Japan, Thailand and Taiwan.

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