David Sacks is the chief executive officer of Zenefits. He has been an entrepreneur, executive and investor in internet technology firms since the late 1990s. As a result of Yammer’s acquisition by Microsoft in July 2012, he served as corporate vice president in Microsoft’s Office Division. On 10 December 2014 he joined Zenefits, a San Francisco based startup company, as COO. On February 8, 2016 he was promoted to CEO following the departure of Zenefits Founder Parker Conrad.