Tumblr founder and CEO David Karp is stepping down after more than 10 years.

"I beg you to understand that my decision comes after months of reflection on my personal ambitions, and at no cost to my hopefulness for Tumblr’s future or the impact I know it can have," Karp wrote in a letter to employees.

A spokesperson for Tumblr parent company Oath confirmed the news, saying the company's COO, Jeff D'Onofrio, will oversee Tumblr after Karp's departure,

David Karp will depart Oath by the end of the year. David founded Tumblr ten years ago as a space for the world’s creators, and we thank him for his commitment and passion driving the growth of the platform to almost 380 million blogs and over 155 billion posts. Going forward, Jeff D'Onofrio, President and COO of Tumblr, will continue to lead the team.

Though the longtime CEO, who together with developer Marco Arment founded Tumblr in 2006, was never as high profile as other tech CEOs like Mark Zuckerberg or former boss Marissa Mayer, he was widely loved and respected among Tumblr's legion of hardcore fans.

Karp sold Tumblr to Yahoo in 2013 in a staggering $1.1 billion cash deal. The acquisition was among Mayer's most high profile acquisitions—and later became one of the former Yahoo CEO's biggest flops.

Despite promising "not to screw it up" in 2013, the site declined in popularity following the acquisition and ambitious sales goals went unmet. Yahoo was eventually forced to write down more than half $1.1 billion it paid for Tumblr.

Source: Mashable