A profile of Uber’s CEO, Travis Kalanick. His leadership is scary.

In a quest to build Uber into the world’s dominant ride-hailing entity, Mr. Kalanick has openly disregarded many rules and norms, backing down only when caught or cornered. He has flouted transportation and safety regulations, bucked against entrenched competitors and capitalized on legal loopholes and gray areas to gain a business advantage. In the process, Mr. Kalanick has helped create a new transportation industry, with Uber spreading to more than 70 countries and gaining a valuation of nearly $70 billion, and its business continues to grow.

…Crossing that line was not a one-off for Mr. Kalanick. According to interviews with more than 50 current and former Uber employees, investors and others with whom the executive had personal relationships, Mr. Kalanick, 40, is driven to the point that he must win at whatever he puts his mind to and at whatever cost – a trait that has now plunged Uber into its most sustained set of crises since its founding in 2009.

“Travis’s biggest strength is that he will run through a wall to accomplish his goals,” said Mark Cuban, the Dallas Mavericks owner and billionaire investor who has mentored Mr. Kalanick. “Travis’s biggest weakness is that he will run through a wall to accomplish his goals. That’s the best way to describe him.”