Frenchman Loic Serra is to become Ferrari's chassis technical director.
The 52-year-old, formerly performance director at Mercedes, will replace Enrico Cardile, who left in July to join Aston Martin as chief technical officer.
Ferrari said in a statement that Serra would start his role on 1 October.
Enrico Gualtieri continues as power-unit technical director.
Serra worked for the BMW Sauber team from 2006 before joining Mercedes when BMW withdrew from F1 at the end of 2009, rising to become performance director in 2019.
Ferrari initially announced that Serra would join as head of chassis performance engineering.
His promotion to technical director comes after a reassessment of the team’s technical structure by boss Frederic Vasseur following Cardile’s departure.
Vasseur has been acting technical director since Cardile left the team.
Serra’s switch to Maranello will reunite him with Lewis Hamilton, with whom he has worked at Mercedes, when the seven-time champion joins Ferrari at the start of next year.
Ferrari had explored the possibility of signing Adrian Newey following the celebrated designer’s decision to leave Red Bull in April.
But talks broke down in the summer and the 65-year-old is set to move to Aston Martin, who have scheduled a news conference for 10 September, when Newey’s new role is expected to be announced.