After around three years in the role of managing director at DDB, Justin Mowday has moved up the chain and been named as chief executive, with Sandy Moore, who has been with the agency for 23 years—and at the top since 2007—stepping back to a part-time role. And in another big change, Mowday will be working closely with Chris Riley, who is moving from his role as managing director at OMD into the newly created role of chief operating officer.