For Lyft, it felt like every day of the company's life was leading to this one.

It was August 5, 2014, a Tuesday, and the ride-hailing company was a day away from showing the world something it had been toying with building for the past two years: Lyft Line, its carpooling service, which allows strangers taking a similar route to share a ride. Lyft, wary of spying from its rival Uber, had acqui-hired two outsiders to cloak-and-dagger themselves away and build Lyft Line in secret. It had only ever been tested internally with 50 employees, and the project had a red-herring codename that hinted at a delivery product. The dramatic reveal was scheduled for an all-hands meeting Wednesday morning, 9 a.m. San Francisco time, where Line's two creators were supposed to hit a button in front of the whole company and make the product go live — except that on Tuesday evening, Uber suddenly published a blog post saying it was beta-testing a carpooling product, UberPool.

Lyft cofounder and CEO Logan Green was stunned. He'd been dreaming of sharing rides since 2005, when he'd seen locals in Zimbabwe create informal carpools among people headed the same direction. After Lyft's debut in 2012, he'd had to wait two years while the company built up its ride-hailing business before it was ready to handle a Lyft carpool service – and now Uber had beaten him to the punch. Competition between Uber and Lyft headquarters has always been an anything-goes, elbows-out race, but this one stung. (These days, in an attempt to prevent sabotage, both companies systematically block the other's employees from using their service.)