Doug Field used to work for Apple, but has been working at Tesla since 2013. Now he’s returning to Apple to work on Project Titan, Apple’s self-driving car, with Bob Mansfield.

Field had been managing Tesla’s engineering and production. In May, Tesla said he was taking time off to spend with his family, but wasn’t leaving the company. Come July, however, Tesla announced he wasn’t working for the company any more.

Apple told Reuters that Field has returned, but didn’t elaborate on what his role is. Previously, he worked with Mansfield on the Mac computer product line.

[Tim Cook: Apple is Making Self-driving Car Software]

[Analyst Says Apple is Still Making a Car]

Apple has been secretive about its self-driving car project and still hasn’t confirmed it exists. That said, Apple has permits in California for road testing autonomous cars, reportedly has a large team working on the project, and now Doug Field has come back to work with Bob Mansfield—the man who reports say is heading up Project Titan.

Considering the number of top-level engineers with autonomous car and car design experience Apple has on its payroll, Project Titan is still progressing.