Also see After stint at Tesla, Doug Field returns to Apple to work on Project Titan w/ Bob Mansfield (9to5Mac)
"Here’s some interesting hiring news I’ve heard through the little birdie grapevine: Doug Field — who left Tesla in May after overseeing Model 3 production — has returned to Apple, working in Bob Mansfield’s project Titan group. Apple spokesperson Tom Neumayr confirmed with me only that Field has returned to Apple, but no one should find it surprising that he’s working on Titan.Doug Field Returns to Apple After Leaving Tesla -- Daring Fireball
Field previously worked at Apple as a VP of Mac hardware engineering before leaving for Tesla in 2013. So he spent years working closely (and successfully) with Mansfield on Mac hardware, and spent the last few years as senior VP of engineering at the world’s premier electric carmaker. That makes Field a seemingly perfect fit for Titan."