Thirty-four year old Twitter co-founder, Jack Dorsey, has returned to lead the microblogging service's product team and be the company's executive chairman.

The second largest shareholder in Twitter announced his return on Twitter on Monday.
“I'm thrilled to get back to work at @Twitter leading product as executive chairman,” wrote Dorsey.
He said he will retain his role as the CEO of the mobile payments company he founded, Square.
Dorsey remained a non-executive chairman of Twitter after he stepped down from the CEO role in October 2008, but he had remained outside its day-to-day operations until recently.
Fellow co-founder, Evan Williams, had run Twitter following Dorsey’s departure until last October when Williams appointed Feedburner founder Dick Costolo as his replacement.
Dorsey had reportedly reconnected with Twitter’s management only after Williams agreed to step down, according to a recent profile by Vanity Fair.