Julia Hartz, 37
Hartz has worn many hats at Eventbrite. Together with her now husband, Kevin, she cofounded the online ticketing startup in 2006. In those early days, she fielded customer support calls (often late at night). As the company grew, she played a role in its marketing and recruiting efforts, before becoming CEO last year. Since she became chief executive, the unicorn company — which raised $200 million in funding and generated $8 billion in gross ticket sales __ has officially reached profitability.
40 Under 40