LONDON — Last week J.W. Anderson, as the hot young British designer is known, was in his studio in Dalston, the rough East London area far from the city center.

On Friday, he was at 10 Downing Street, the official home of the British prime minister, hobnobbing with Samantha Cameron, Victoria Beckham and Donatella Versace — especially Ms. Versace, for she has asked Mr. Anderson to take over as creative director of Versus, the brand that once was her baby and is now an online operation.

“It is important for me to have someone of a new generation who is familiar with the Internet,” says Ms. Versace, who previously employed another British whiz kid: Christopher Kane, a fellow inhabitant of grungy Dalston, who is now being backed by the luxury group PPR.