Jack Dorsey fashion design. As the service began to grow in popularity, Dorsey chose the improvement of uptime as top priority, even over creating revenue – which, as of 2008, Twitter was not designed to earn. Dorsey described the commercial use of Twitter and its API as two things that could lead to paid features. He describes his three guiding principles, which he says are shared by the company, as simplicity, constraint and craftsmanship. On October 16, 2008, Williams took over the role of CEO, while Dorsey became chairman of the board. On March 28, 2011, Dorsey returned to Twitter as Executive
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