Paul Sheerin has left his job as manager of Arbroath to take over as U20 coach at Aberdeen.
The 39-year-old had been in charge at Gayfield since May 2010, making him the second-longest serving SPFL boss behind Dick Campbell of Forfar.
A former Aberdeen player, Sheerin replaces Neil Cooper, who departed Pittodrie last month.
Dons chief executive Duncan Fraser told the club website: "Following a comprehensive process, Derek McInnes identified Paul as the person he wanted for this vital role."
