David Karp (born July 6, 1986)[1] is an American entrepreneur and blogger, best known as the founder and former CEO of the microblogging platform Tumblr.[2][3] Karp began his career, without receiving a high school diploma, as an intern under Fred Seibert at the animation company Frederator Studios, where he built the studio's first blogging platform and conceived, wrote, and edited their first in