In April 2010 he left Force India to join the Sauber team, replacing Willy Rampf as Technical Director.
[5] On 6 September 2012, it was announced that Key had joined Scuderia Toro Rosso as Technical Director, replacing Giorgio Ascanelli.
[6] On 26 July 2018, McLaren confirmed that Key had agreed to become technical director of the team, replacing the ousted Tim Goss.
On 22 February 2019, it was announced that Key would join McLaren from 25 March 2019, just after the Australian Grand Prix.
[4] He once again worked under Andreas Seidl, CEO of Sauber Group, who had served as Team Principal during the pair's time at McLaren.