Jan Koum

Jan Koum is a Ukrainian-born American entrepreneur and computer engineer. In February 2009, he co-founded the mobile real-time messaging app WhatsApp with Brian Acton and served as its CEO.

Facebook acquired WhatsApp in February 2014, at which time Koum became a managing director at Facebook, in addition to his position as CEO of WhatsApp.

Before founding WhatsApp, Koum studied math and computer science at San Jose State University, and worked as an infrastructure engineer at Yahoo.