Sheryl Sandberg is one of the best known business people in the world. As Mark Zuckerberg’s chief operating officer and No. 2, she has been a power behind the scenes at Facebook for more than a decade. She supercharged Facebook’s business strategy, including its data-driven advertising platform, and has helped transform the company’s finances. This year she’s been central to Facebook’s response to revelations that groups linked to the Russian government used Facebook to influence the 2016 US elections. Sandberg also had to answer for another scandal involving the collection of 87 million Facebook users’ information by a political data firm. Last week, Facebook took another public hit: The company revealed that a major hack exposed information from 50 million accounts. But Sandberg is probably best known outside Silicon Valley as a best-selling author who jump-started a movement in female leadership. Her 2013 book “Lean In: Women, Work and the Will to Lead” led a national debate over how women should be empowered to pursue their professional ambitions. A second book — “Option B: Facing Adversity, Building Resilience, and Finding Joy” — was borne from the pain she experienced when she found herself suddenly widowed with two young children in 2015. She used her personal story to again start a public conversation, this time about how to deal with loss and build a future after the unthinkable happens. CNN Business, in the first of a new feature that will explore the inner lives of business leaders, asked Sandberg in an email interview about her style as a manager, what it takes to be successful and what she wishes Facebook had done differently. What does it take to run a successful business? I strongly believe in ruthless prioritization. Sometimes people think of prioritization as only doing things that will have a positive impact on your business. But ruthless prioritization means only focusing on the very best ideas. It means figuring out the 10 things on your list and, if you can’t do all 10, doing the top two really well. Ruthlessly prioritizing can get hard because you’re always trying to do more, but it’s one of the best and most important ways to stay focused. How do you keep innovating and stay on top of trends in such a fast-paced business world? At Facebook, we think about meeting people where they are and anticipating where they’re going. For example, when we decided to shift to mobile, we made sure all our products were designed mobile first. If a team came into a product review with only a desktop version of a product, they had to go back to the drawing board. It felt like a risk at the time, but it turned out to be one of the best things we’ve done for our business. In light of the recent criticism of Facebook, is there anything you wish you’d done differently? Absolutely. In September we had a serious security issue that impacted over 50 million people who use our product. We acted quickly to protect their accounts but we need to continue improving our security to prevent these kinds of things from happening in the first place. Elections are another area where we are also investing heavily to prevent misuse on Facebook. For many years, we were too focused on the good and not focused enough on the ways people could abuse our services for the bad. The investments we’re making in security are very important — as is our work with experts, government and other companies. Are you worried about the impact of tech addiction? Many people understandably wonder whether all the time we spend on our phones and social media is bad for us. This is something I think about a lot — not just because it’s part of my job but because I’m a mom and someone who’s trying to be more present in my own life. We’ve found that when we use social media to actively engage with people we care about by commenting on their posts and sending messages, it’s good for our well-being because we feel more connected. But when we passively scroll or consume content, it may not be as good for us. That’s why we made some changes earlier this year so you now see more posts from friends and family in your News Feed and less of the more passive content. And in August, we rolled out three new features on Facebook and Instagram so people can see how much time they’ve spent on each app, set a limit on that time, and mute their notifications. We want people to better manage their experience and connect with people who matter most — both online and off. What advice would you give someone with your job (or who wants to be in your job)? Ask for feedback — and take it well. Even when you’re in positions of leadership, it’s important to listen to feedback and use it to do better. People who do this will keep learning and growing. It also builds great trust within your teams. What do you wish you’d learned early in your career? There’s no straight path to where you’re going. If you try to draw the line, you won’t just probably get it wrong — you’ll also miss big opportunities. When I was graduating college, Mark was in pre-school and the Internet had just been invented. Careers are not ladders but jungle gyms. You don’t have to have it all figured out. But I do think you can have two goals at once: a long-term dream and a short-term plan. Set personal goals for what you want to do in the future and what you want to learn in the next year-and-a-half. Ask yourself how you can improve and what you’re afraid to do — that’s usually the thing you should try. What mentor or teacher has influenced your career most, and how? When we think about mentors, we tend to think about the people who are more senior than us. In my experience, the most underrated mentors are our peers. When I was deciding whether to make the jump from government to tech and move to Silicon Valley, my peers were the ones who encouraged me to do it. Peer mentorship is also the idea behind the Lean In community. Women and men have started more than 35,000 Circles in 160 countries. Circles are peer groups that meet regularly to encourage each other to achieve their dreams, whatever they may be. I’ve heard so many inspiring stories over the years about how members are helping each other believe in themselves. In fact, 85% of members attribute a positive change in their lives to their Circle and almost two-thirds of women in Circles are taking on a new challenge. This is proof that we don’t have to look up to find some of the best support systems.