Uber has to find a new CEO - Here are 8 likely candidates

Now, though, that person will get to call themselves CEO.

The ride-hailing company's former chief executive, Travis Kalanick, resigned the post on Tuesday after getting a letter from investors demanding his departure. At the time he received the letter, he was in Chicago to interview a candidate to be Uber's chief operating officer. Up until Kalanick's resignation, filling that position was the company's top priority.

Now, Uber's board is putting on hold the search for a partner for Kalanick, to start looking for a leader for the new Uber. (Kalanick, though, will have a role in finding his replacement.)

It won't be easy to find an exec willing to take on turning around the embattled company, but here's a list of some of the likely candidates for the job: