Shear's resignation adds to a recent exodus of leadership under CEO Andy Jassy. Earlier this month, Ring CEO Jamie Siminoff announced he was stepping down from his role at the home security subsidiary. Last year, executives overseeing Amazon's Alexa and hardware research and development group, known as Lab126, exited the company. Last July, public policy chief Jay Carney announced he was leaving to join Airbnb, and 23-year Amazon veteran Dave Clark resigned as retail chief the same month.