SAN FRANCISCO — Travis Kalanick, the chief executive of Uber, visited Apple's headquarters in early 2015 to meet with Timothy D. Cook, who runs the iPhone maker. It was a session that Mr. Kalanick was dreading.

For months, Mr. Kalanick had pulled a fast one on Apple by directing his employees to help camouflage the ride-hailing app from Apple's engineers. The reason? So Apple would not find out that Uber had been secretly identifying and tagging iPhones even after its app had been deleted and the devices erased — a fraud detection maneuver that violated Apple's privacy guidelines.

But Apple was onto the deception, and when Mr. Kalanick arrived at the midafternoon meeting sporting his favorite pair of bright red sneakers and hot-pink socks, Mr. Cook was prepared. "So, I've heard you've been breaking some of our rules," Mr. Cook said in his calm, Southern tone. Stop the trickery, Mr. Cook then demanded, or Uber's app would be kicked out of Apple's App Store.

For Mr. Kalanick, the moment was fraught with tension. If Uber's app was yanked from the App Store, it would lose access to millions of iPhone customers — essentially destroying the ride-hailing company's business. So Mr. Kalanick acceded.

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.

But the previously unreported encounter with Mr. Cook showed how Mr. Kalanick was also responsible for risk-taking that pushed Uber beyond the pale, sometimes to the very brink of implosion.

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.