With Jassy as CEO and Bezos becoming executive chairman this year, there's been a scramble for leadership positions beneath them, as well as many departures. Dave Clark became CEO of Amazon's worldwide consumer business this year, taking over from Jeff Wilke, who left the company. Clark oversees everything from Amazon's warehouse and shipping network to marketing and the Prime membership program. In its turn, Adam Selipsky took over from Jassy as CEO of Amazon Web Services, t