On Thursday, 16 July, he tweeted: ‘Thank you @Twitter for an extraordinary ride. It continues to be much than a company. #movement.”
He has led Twitter’s communications team since 2012 and before that held an executive communications role at Google.
His exit follows former CEO Dick Costolo’s departure earlier this month.
The move comes as the eight-year old social platform continues to find itself in turmoil as it struggles to add new users.
Co-founder Jack Dorsey is currently serving as interim CEO as the company searches for someone to fill the role.
