Jack Dorsey has stepped down as head of the social media platform he co-founded a decade and a half ago.

Board member and former Chief Technology Officer Parag Agrawal, 45, who joined Twitter in 2011 and has been serving as the CTO since 2017, was appointed CEO, effective immediately, and Dorsey will remain a member of the board until his term expires at next year’s stockholders’ meeting, the company said.

Dorsey said in a statement released by Twitter: “I’ve decided to leave Twitter because I believe the company is ready to move on from its founders.

“My trust in Parag as Twitter’s CEO is deep. His work over the past 10 years has been transformational. I’m deeply grateful for his skill, heart, and soul. It’s his time to lead.”

Dorsey warned of potential pitfalls of a company founder staying on for too long.

He said “There’s a lot of talk about the importance of a company being ‘founder-led’.

“Ultimately I believe that’s severely limiting and a single point of failure.”

In an email to company employees he posted to Twitter on Monday, Dorsey denied that he was being pushed out of the company’s leadership and claimed to be resigning so that the company can move on from its founders.

“I’ve worked hard to ensure this company can break away from its founding and founders,” he wrote, noting that “there aren’t many founders that choose their company over ego.”

“I know we’ll prove this was the right move,” he added.