Reid Hoffman knows a thing or two about picking winners. The billionaire investor co-founded LinkedIn, and made early bets on companies like Airbnb and Facebook. He's also one of Silicon Valley's multi-hyphenates: a partner at VC firm Greylock, author of best-selling books and host of the popular "Masters of Scale" podcast.
Given that he's seen so many business plans and pitches by start-up CEOs over the years, what is the single most important quality he looks for in founders?
"There are table stakes," he told me during a recent conversation for "The Art of Leading" interview series. "But one of the more unique characteristics that I tend to look for is an infinite learning curve, because most of the time the businesses that I'm investing in are breaking new ground and creating a new area. You have to have a sense of, 'How am I going to learn a new area?' So I'm looking for an ability to be learning constantly, and fast."
So what is Hoffman's single best job interview question to determine if they have that quality?
"You take them to some point in their career and you say, 'What would you tell yourself if you could now call your younger self and tell yourself what you've learned in order to be better?'
"And it's not, 'Oh, I learned this fact,' but a pattern of thinking. They're learning in a way so that they can share it with their team. They can repeat it as, here's something we've learned about how we can make decisions better, how to lead better, how to manage better, and that's encapsulated in something that you could tell younger self."
And how would he answer his own question? What would he tell his younger self?
"One thing I learned as a start-up CEO, and started embodying in my practice, is to always be recruiting," Hoffman said. "One of the classic mistakes that a younger CEO-founder makes is to think, 'Well, I recruit when I'm looking for a person for a specific job, like a head of marketing or a head of engineering.'"
"In fact, you want to be constantly meeting the best people and expecting that your business is going to grow," he added. "So you're meeting the people that you're anticipating that you're going to be recruiting in a year or two. So the lesson is to always make time every week to build relationships with key talent that I need to recruit in my company."
That's good advice for everyone, not just start-up founders: Always make time to build your network.
Adam Bryant is a CNBC contributor and managing director of Merryck & Co., a senior leadership development and executive mentoring firm. A veteran journalist, Bryant interviewed more than 500 leaders for the "Corner Office" feature he created at the New York Times. Parts of this interview were edited for clarity and space.