Google’s astonishing success in its first decade now seems to have been almost inevitable. But step inside its systems infrastructure group, and you quickly learn otherwise. The company’s meteoric growth depended in large part on its ability to innovate and scale up its infrastructure at an unprecedented pace. Bill Coughran, as a senior vice president of engineering, led the group from 2003 to 2011. His 1,000-person organization built Google’s “engine room,” the systems and equipment that allow us all to use Google and its many services 24/7. “We were doing work that no one else in the world was doing,” he says. “So when a problem happened, we couldn’t just go out and buy a solution. We had to create it.”

A version of this article appeared in the June 2014 issue of Harvard Business Review.