Twitter Co-Founder Jack Dorsey, who was pushed out of the company when chief executive back in 2008, is set to return full time to lead product development.

He replaces fellow co-founder Evan Williams, who has stepped back from his daily involvement with the microblogging site, but will remain on the board.

The announcement was made, or should I say, Tweeted by current chief executive Dick Costolo who wrote that he was “excited” by Jack’s return.

Mr Dorsey followed this up with a tweet of his own, stating that he was “thrilled”.

Twitter celebrated its fifth birthday last week.