(Reuters) -Tesla's best-selling Model Y's program manager, Emmanuel Lamacchia, announced his departure on Sunday after nearly eight years, marking another high-profile exit from Elon Musk's electric vehicle company.

The departure came hours after the head of Tesla's Cybertruck program, Siddhant Awasthi, also said he was leaving the company. Awasthi, who started his career at Tesla as an intern eight years ago, played a key role in bringing the stainless-steel pickup to market and recently took over the Model 3 program.

Lamacchia joined Tesla in 2018 and has spent over four years overseeing the Model Y program, managing its production and international rollout across multiple factories.

"What a journey it's been... from leading NPI (new product introduction) for Model 3 and Model Y variants to becoming the Vehicle Program Manager for Model Y, the best-selling car in the world," Lamacchia wrote in LinkedIn post.

As Tesla pivots toward robotaxis and AI-driven projects, the automaker has lost several senior program managers over the past year, including Daniel Ho, credited with the Model 3 launch, and David Zhang, who oversaw Model S and X programs.

The automaker posted record deliveries in the third quarter, driven by a rush of U.S. buyers trying to grab a $7,500 tax credit before it expired on September 30. However, analysts expect a sharp slump in the fourth quarter as the incentive for EV purchases vanishes.