Key Tesla engineer won't return to company

Doug Field, Tesla's senior vice president for engineering, is leaving the Silicon Valley electric automaker, one day after the company announced it'd successfully met production targets on its Model 3.

Why it matters: Field, who has been on leave since May, is one of numerous top Tesla executives who have left the company in recent months. The turnover comes at a critical time for the automaker that's seeking to further ramp up production of the Model 3 sedan while preparing to launch new products including an electric semi-truck.