The first time I met Satya Nadella, I committed what I thought was a cringeworthy faux pas. It was summer 2015, and he was just over a year into his role as Microsoft Inc.’s chief executive officer, and the value of the company that day stood at about $370 billion.

“Is that an iPad?” he asked, on camera, as I pulled out the device so I could have my questions at hand. On reflection, it was really no big deal. But as a still somewhat junior reporter, I was worried I was rubbing his face in it. The success of the iPad had blown all of Microsoft’s tablet efforts out of the water. And the iPhone, of course, had made mincemeat of Windows Phone. Nadella’s predecessor, Steve Ballmer, had not been quick enough to grasp the mobile revolution — “there’s no chance that the iPhone is going to get any significant market share,” he said — and had left Microsoft weak.