Before Tumblr, Founder Made Mom Proud. He Quit School. (Published 2013)

David Karp, Tumblr’s founder, in 2011. He left Bronx High School of Science at 14 to focus on computers, on his mother’s advice.Credit...James Estrin/The New York Times When David Karp was 14, he was clearly a bright teenager. Quiet, somewhat reclusive, bored with his classes at the Bronx High School of Science. He spent most of his free time in his bedroom, glued to his computer. But instead of t