Vision, strategy, culture, and shareholder value are all key responsibilities of a CEO. But to quote Jim Collins' must-read book, a truly great leader is dedicated to "having the right people on the bus." This analogy for hiring and retaining brilliant leaders is the perfect way to think about a CEO's responsibility to recruit the right leaders in the right roles so that the bus, aka the company, is optimized for success.

Top CEOs know this. To maintain a high level of productivity and innovation throughout the company, a true leader understands the value of filling his or her ranks with people who are as smart, if not smarter, than them.

We asked this year's Top CEOs winners to reveal how they recruit the best talent. Here's what they said. This is one you'll want to bookmark!

Man with hands around lighted cartoon depictions of people in the center of a larger line.

Image source: Getty Images.

1. Look for candidates with talent and passion

"Throughout my career I've learned that, while skills and experience can open the door, getting the job requires demonstrating character, commitment and passion," says Michael Mahoney, CEO of Boston Scientific. "When I interview people, I ask what they've done to solve challenging problems. I'm looking for people who embrace change, and are willing to "own the situation" vs. blame the circumstance. We're looking for people who are resilient and willing to try new things."

2. Happiness goes a long way

"We view employee happiness as a competitive advantage," says Gireesh Sonnad, CEO of Silverline. "Employees that are excited and engaged develop strong relationships with clients, which in turn ensures our customers are also happy and having a positive experience. Employee well-being can also impact strength in talent acquisition. We encourage our employees to bring in talent that will help grow the organization in a way that they can be proud of as well. The more talented people we have, who enjoy the environment that we have created, the more successful we can become."

3. Referrals are just as valuable as ever

For Lynsi Snyder, CEO of In-N-Out, not only does a candidate's disposition matter, but she has years of experience sourcing hires from her existing workforce.

"We look for great smiles and people who love being around people. We also want Associates who have a natural commitment to serving our customers. We can teach just about everything else. We find a surprising number of our best new hires are referrals from current Associates. Great people tend to hang out with other great people."

4. Always be evolving

Today's fast-paced world of recruiting and technological innovation doesn't allow for year-old strategies and tactics. For KPMG CEO Lynne Doughtie, the need to be constantly evaluating business needs is key for recruiting. "Technology is rapidly changing the business landscape -- and our profession -- and we must ensure we have the talent with the requisite skills to meet the fast-evolving needs of our profession," says Doughtie. "For example, across all of our service areas -- we need professionals with data and analytics experience and knowledge of emerging technologies, and our talent acquisition strategies reflect that. Today's marketplace is creating never-before-seen opportunities, so we seek people with an innovative spirit that embrace change and have the vision and passion to steer our firm into the future."

5. Build strong partnerships to expand recruiting pools

With healthcare being the fastest-growing industry, competition is stiff for top talent. For Bernard J. Tyson, chairman and CEO of Kaiser Permanente, this, combined with the industry's innovation, makes partnerships an imperative. "Our business needs are continually evolving as we transform healthcare from within," says Tyson. "In support of our strategy, we have created targeted partnerships with schools and universities, national organizations, and our own employees to tap into specific talent pools, such as those from consumer-focused industries. We also run an incredibly large IT business that must be competitive to attract IT talent from around the country and world. We also monitor and analyze our workforce for our ability to meet our business needs, and we tweak our recruiting strategy accordingly."

6. Ask interview questions to get at whether a candidate is naturally curious and a risk-taker

"What we look for is people that are curious," insists Craig Thompson, CEO of Memorial Sloan Kettering. "People that want to understand and improve health through understanding cancer...two real skills that are hard to balance. People that show that high level of common sense but at the same time, they have to be ambitious for what they want to achieve. The status quo in cancer care is not good enough for anybody. If they come in saying, "I just want to be able to do what we do today," that is not enough. We want them to be pushing the boundaries."

7. Don't forget that some of the simplest questions can yield the most insight

The first question that Zoom Video Communication CEO Eric Yuan asks candidates is "What book have you read recently?" For him, this question reveals whether a candidate is hungry to learn and better themselves. "If she says, 'Oh, I'm so busy, I haven't I read any book in almost a year, I would say, 'Ah, sorry.' However, some candidates say, 'Yes, I've just read a new book XYZ and some very interesting parts of it were XYZ.' This is an indicator to me that they are always learning, that they have made that a priority."

This article originally appeared on Glassdoor.com.