Andrei Herasimchuk, director of the design team at Twitter, has left the company, according to AllThingsD.

His departure comes a week after the company named Mike Davidson, CEO and founder of Newsvine, as Twitter’s new vice president of design.

Two more designers left the company in September to join other start-ups.

Herasimchuk was with Twitter for a year and a half, and was previously a senior director of product design at Yahoo.