WhatsApp Co-Founder to Leave Company After Reported Disagreements with Facebook Jan Koum, who co-founded WhatsApp and served as the company’s CEO, announced that he is stepping down in a Facebook post. It's been almost a decade since Brian and I started WhatsApp, and it's been an amazing journey with some of the best people. But it is time for me to move on. I'm taking some time off to do things I enjoy outside of technology, such as collecting rare air-cooled Porsches, working on my cars and playing ultimate frisbee. Koum did not give a reason for his departure but The Washington Post reports that he had disagreements with Facebook how it handled user data. Facebook CEO Mark Zuckerberg commented on Koum’s post, wishing him well. I’m grateful for everything you’ve done to help connect the world, and for everything you’ve taught me, including about encryption and its ability to take power from centralized systems and put it back in people’s hands.