Tumblr CEO David Karp, who founded the blogging service back in 2007, is leaving the company.
Karp posted the announcement on his personal blog Monday after sharing it internally with Tumblr’s team. Jeff D'Onofrio, Tumblr’s president and COO, will take over while the company seeks a permanent replacement, according to The Verge.
Tumblr has been through some massive organizational changes over the past five years. Yahoo first purchased Tumblr for a little over $1 billion back in 2013. Then Verizon purchased Yahoo, including Tumblr, for almost $4.5 billion in a deal that closed earlier this year, combining Yahoo and AOL into a new subsidiary called Oath.
It’s not immediately clear why Karp is leaving, though a decade at one company, even one you founded, is an eternity in the world of tech. “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,” he wrote.
This article originally appeared on Recode.net.