Introduction Uber started as a ridesharing company with a simple yet ambitious mission: make transportation as reliable as running water, everywhere, for everyone. When the company focused on ridesharing, most back-end systems were built around a trip, a rider, and a driver. Since it was the only LOB (line of business) at the time, any payment-specific operations were implemented directly into the ridesharing system. For example, supporting Apple Pay® was implemented on the Rides back end. When ...