Uber's rise to the top of the ride-sharing industry is due in large part to its hard-charging founder and chief executive, Travis Kalanick.
But while Kalanick has steered Uber to a valuation in the tens of billions of dollars with operations worldwide, he and the company have been bruised by this aggressiveness, prompting a search for a steadier hand at the wheel.
After a series of missteps and embarrassments for Uber and Kalanick, the San Francisco startup has acknowledged it is searching for a number-two executive to handle some of the day-to-day management tasks.
Kalanick, 40, is known for taking a hard line in battles with regulators and taxi operators in markets opposing the entry of a new kind of competitor.
But he has been humbled by the events of the past month, which included the release of a dash-cam video showing him berating and cursing at one of Uber's drivers.
"To say that I am ashamed is an extreme understatement," Kalanick said in a memo to employees after the incident.
The video, he said, was "a stark reminder that I must fundamentally change as a leader and grow up. This is the first time I've been willing to admit that I need leadership help and I intend to get it."
Uber has also been rocked by disclosures about a culture of sexism and its covert use of law enforcement-evading software.
Kalanick also made a hasty exit from a business advisory panel for President Donald Trump after a consumer boycott campaign fueled by concerns that he was aiding a leader with divergent values.
But Kalanick has long been known as someone who drives close to the edge.
The California native dropped out of the University of California-Los Angeles (UCLA) to start a file-sharing service called Scour, which pre-dated the popular service Napster but ran into similar legal challenges.
Scour faced lawsuits from major music and film industry groups claiming $250 billion in damages, and was forced to declare bankruptcy in 2000.
After that failure, he launched another file-sharing service called Red Swoosh.
Kalanick frequently recounts his story for the idea of Uber -- saying he and co-founder Garrett Camp were unable to find a taxi during a 2008 visit to Paris, and dreamed up the idea of pushing a button on a smartphone to summon a ride, and called it UberCab.
The name was shortened to Uber, which launched in 2010 in San Francisco, and now is active in more than 500 cities around the world, with an estimated valuation of $68 billion.
According to Forbes magazine, Uber's lofty value gives Kalanick a personal net worth of $6.3 billion.
- Bumps in the road -
The road has not always been smooth.
Last year, Uber had to quit the Chinese market and agree to a partnership with the local market leader, Didi Chuxing.
Uber and Kalanick have faced protests and traffic tie-ups from angry taxi drivers, with demonstrators in Paris setting fire to some vehicles.
Some Uber drivers have sued to be recompensed as employees, rather than independent contractors, and others have complained that the mobile app used by Uber lacks the ability to offer tips.
Uber has also faced criticism for its "Greyball" software that may be used to avoid authorities, and its "God View" which could be used to spy on riders.
After revelations about "Greyball," Uber announced it would not use the program to evade regulators.
Kalanick is known for being defiant in the face of criticism but his recent mea culpa is not the first time he has tried to soften his image.
"I realize that I can come off as a passionate advocate for Uber," he was quoted as saying in 2015 by The Wall Street Journal.
"I'll be the first to admit I'm not perfect, and neither is this company."