Earlier this year, Khosrowshahi, who took over as CEO in 2017, said that the process of finding a new CFO was taking longer than he would have liked. He said he was being "picky," wanting to ensure whoever was selected for the important role was exceptional. Uber reportedly offered the position to VMware CFO Zane Rowe earlier this year, though he later turned it down.

Chai's job certainly won't be easy. He's joining a company that has consistently posted net losses quarter to quarter and is preparing to go public in late 2019. That's not a lot of time to rein in those losses.

"Uber is one of the world's most iconic and exciting technology companies, and I'm honored to join as CFO," said Chai. "I look forward to working closely with Dara and team as we build on the company's strong growth and forward momentum."