Ride-hailing startup Uber's top executive Sherif Marakby, working on the venture's self-driving cars, has quit a year after joining Uber. Marakby, who spent 25 years at Ford before Uber, is one among many other top-level executives who recently quit Uber's self-driving car operations. His exit comes amid Uber facing a lawsuit alleging it stole Google spinoff Waymo's self-driving car technology.