Jack Dorsey Chairman after Dick Costolo replaced Williams as the CEO. On June 10, 2015, Costolo announced that he was resigning as CEO of Twitter, effective July 1, 2015. Dorsey would assume the post of Interim CEO upon Costolo's departure. He was named permanent CEO of Twitter on October 5, 2015. On the day after the controversy about Twitter's new algorithms for tweets, Dorsey responded to the trend, saying it was only a hoax. In May 2016, Dorsey announced that Twitter would not count photos and links in the 140-character limit to free up more space for text. This move was an
Evan James Williams to stonemason James and Elizabeth (née Lloyd) Williams. He attended Llanwenog Primary School, then Llandysul School, where he was a close friend of Evan Tom Davies and, like Davies, excelled in mathematics. From there Williams, at the age of 16, won a £55 scholarship to Swansea University where he studied physics and attained a first-class honours degree in 1923. From Swansea, Williams went into physics research at Manchester University's physics laboratories under Lawrence Bragg. At Manchester he attained a doctorate in physics in 1926 for his work with Bragg, studying X-rays in gases, then a second degree at the Cavendish