SAN FRANCISCO, Feb. 22 (Xinhua) -- Twitter co-founder Evan Williams said Friday he is leaving the board of directors of the U.S. social networking giant at the end of the month.
"I'm very lucky to have served on the @Twitter board for 12 years (ever since there was a board). It's been overwhelmingly interesting, educational-and, at times, challenging," tweeted Williams, who has served as the CEO of Twitter.
While expressing his appreciation for almost 4,000 Twitter employees "who are doing the hard work every day," "I will continue rooting for the team as I focus my time on other projects," he added.
Williams succeeded Twitter founder Jack Dorsey to assume the role of CEO in 2008 until 2010, when he was replaced by Dick Costolo.
He is currently the CEO of Medium, a San Francisco-based online publishing tech company that was launched by himself in 2012.
