Here's Arianna Huffington's memo welcoming new Uber CEO Dara Khosrowshahi

Uber CEO Dara Khosrowshahi

The board had already selected Khosrowshahi as Uber's next CEO in a vote on Sunday. Less well known is that Khosrowshahi was an early advocate of bitcoin.

Khosrowshahi's appointment comes at a time when Uber is trying to recover from a series of crises that culminated in the ouster of its former CEO Travis Kalanick in June. Until this week, Uber was operating without a CEO, COO, CFO, CMO or president.

"This company has to change", Khosrowshahi said in his remarks, according to the company. Uber has spent the better part of this year in crisis mode, weathering allegations of a toxic culture that allowed discrimination, sexual harassment and bullying.

Dents to Uber's image include a visit by executives to a South Korean escort-karaoke bar, an attempt to dig up dirt on journalists covering the company and the mishandling of medical records from a woman raped in India after hailing an Uber ride.

In comparison, Khosrowshahi's job will be a lot easier: Be charming and commanding, making it clear to Uber's universe that he is ready to be in charge. The venture capital firm argues that special powers Mr. Kalanick negotiated in 2016 - which gave him control over three board seats, including one he occupies - were bestowed under false pretenses and should be nullified. Lawyers for Kalanick and Benchmark, one of Uber's major investors, met for the first time in court Wednesday to hash out an explosive lawsuit. Kalanick was at turns overly aggressive and unnecessarily careless as he grew Uber from a small cab-matching service in San Francisco, in 2009, into the world's most valuable private tech company.

Running Uber will be no easy task.

In an email to Expedia staff, Khosrowshahi said he was "scared" and had "forgotten what life is outside of this place [Expedia]".

He made the comments at a previously scheduled event at Expedia's headquarters in Bellevue, Washington.

"He's adult enough to face the cultural issues at Uber, and he's not stodgy or from a legacy technology company", said Henry Harteveldt, a travel industry analyst at Atmosphere Research who has followed Khosrowshahi's career at Expedia. Born in Iran, he and his family fled the Iranian Revolution and settled in the United States when he was nine years old. It is also a key step towards filling a gaping hole in its top management that at the moment has no chief financial officer, head of engineering or general counsel.