People don’t quit a job, the saying goes — they quit a boss. We’ve heard it so many times that when we started tracking why employees leave Facebook, all bets were on managers. But our engagement survey results told a different story: When we wanted to keep people and they left anyway, it wasn’t because of their manager…at least not in the way we expected.

Of course, people are more likely to jump ship when they have a horrible boss. But we’ve spent years working to select and develop great managers at Facebook, and most of our respondents said they were happy with theirs. The decision to exit was because of the work. They left when their job wasn’t enjoyable, their strengths weren’t being used, and they weren’t growing in their careers.

At Facebook, people don’t quit a boss — they quit a job. And who’s responsible for what that job is like? Managers.

If you want to keep your people — especially your stars — it’s time to pay more attention to how you design their work. Most companies design jobs and then slot people into them. Our best managers sometimes do the opposite: When they find talented people, they’re open to creating jobs around them.

Working with our People Analytics team, we crunched our survey data to predict who would stay or leave in the next six months, and in the process we learned something interesting about those who eventually stayed. They found their work enjoyable 31% more often, used their strengths 33% more often, and expressed 37% more confidence that they were gaining the skills and experiences they need to develop their careers. This highlights three key ways that managers can customize experiences for their people: enable them to do work they enjoy, help them play to their strengths, and carve a path for career development that accommodates personal priorities.

Crafting Jobs for Enjoyment

Many of us have unanswered callings at work — passions that we didn’t get to pursue in our careers. Whether we lacked the talent, the opportunity, or the means to make them our occupations, landing in a different career doesn’t make these passions disappear. They linger, like the professional version of the one who got away. And since we spend the majority of our waking hours at work, there isn’t always time to pursue these unanswered callings as hobbies. So we look for ways to bring our passions into our jobs. Personally, we know a lawyer who missed his dream of being a pilot and so sought out aviation cases, and a teacher who walked away from a music career but brings a guitar to class. But inside organizations, people often need support to craft their jobs.

Managers can play a major role in designing motivating, meaningful jobs. The best go out of their way to help people do work they enjoy — even if it means rotating them out of roles where they’re excelling. A few years ago, one of Facebook’s directors, Cynthia, was leading a large team of HR business partners. She realized that she wasn’t spending her time doing what she enjoyed most: solving problems with her clients. She had taken on more responsibilities managing a large team because of her strength as a trusted adviser to some of Facebook’s key leaders. But once she was in the job, she realized it meant doing less of the work that energized her.

With her manager’s support, Cynthia hired someone new onto the team, with the long-term vision of asking her to run the team and then moving back to an individual contributor role. Cynthia wasn’t just hiring a direct report; she was hiring her future boss. Once the new hire was ramped up, and it was clear that she enjoyed the organizational and people management elements of her job, she and Cynthia made the switch. Cynthia is now thriving, solving problems with the clients she loves so much, and her new hire is leading the team. Keeping Cynthia at Facebook was much more important to her manager than keeping her in a particular role.

Too often, managers don’t know enough about what work people enjoy. It spills out in exit interviews — a standard practice in every HR department to find out why talented people are leaving and what would have convinced them to stick around. But why wait until they’re on their way out the door? One of us, Adam, has worked with companies in multiple industries to design entry interviews. In the first week on the job, managers sit down with their new hires and ask them about their favorite projects they’ve done, the moments when they’ve felt most energized at work, the times when they’ve found themselves totally immersed in a state of flow, and the passions they have outside their jobs. Armed with that knowledge, managers can build engaging roles from the start.

Bringing in Underutilized Strengths

In a world dominated by specialization, we’re long past the era of the Renaissance Man. Once in a blue moon we see one. Marie Curie won a Nobel prize for her pioneering work in physics, and then earned another in chemistry. Richard Feynman transformed electrodynamics, decoded Mayan hieroglyphs, and cracked safes in his spare time. Although few reach this level of accomplishment in multiple fields, many talented people are polymaths. At Facebook, our head of diversity is a former lawyer, journalist, and talk show host; one of our communications leaders used to sing in a rock band; and one of our product managers is a former teacher. Sadly, the narrow job descriptions that companies create stifle their ability to use the full range of their employees’ skills.

Smart managers create opportunities for people to use their strengths. To see how that can play out, let’s consider Chase, who was recently working as a software engineer at Instagram. About six months ago, when his team went through rapid product iteration to introduce new tools and formats, Chase helped lead the team to exceptional results. But he finished the project drained from the extensive coding and cross-functional work — and started wondering whether there were other ways to contribute. Talking with his manager, Lu, he realized that while he had a strong technical background, where he really excelled was building prototypes to help prove concepts quickly and then iterating. But Instagram didn’t have any roles that blended this skill set, and Chase didn’t have a track record in traditional design work.

Lu convinced the design team to take a risk and allow Chase to try a new role for a “hackamonth.” During that time, Chase partnered with Ryan, a product design lead, to quickly build several prototypes that tested novel ways of capturing and sharing. His success not only landed him in a brand-new role that leveraged his strengths but also created the conditions to build a broader team of collaborators with similar skills and interests. According to Lu, “A shift to this role was a no-brainer for Chase and a win for Instagram. All that was missing was the push to make this happen.”

Creating new roles isn’t the only way to let people play to their strengths. In a connected world, a huge part of getting work done is seeking and sharing knowledge. Some estimates suggest that knowledge workers spend more than one-quarter of their time searching for information. It’s up to managers to help them figure out where to turn. As managers learn who knows what, they can connect the dots — or better yet, build a searchable database of experts. The goal is to put employees’ strengths on display so that people know whom to contact.

Making It Possible to Lean In at Work and at Home

In too many situations, opening a door in our careers means closing one in our personal lives. The special project that takes date nights away from our partners. The big promotion that takes weekends away from our kids. The new role across the country that takes us away from our families.

At Facebook, our best managers work with people to minimize these trade-offs by creating career opportunities that mesh with personal priorities. Here’s an example.

Shona, an agency lead, was coming back from maternity leave to a global role where time zones directly conflicted with her parenting. With her manager, Shona developed a prioritization plan for travel. For anything that was important but not essential, she worked with regional colleagues to set up meeting coverage. Shona’s manager also connected her with a mentor in a global role who guided her through her transition. In Shona’s words, “This deep level of support gave me the confidence to return to work fully present and also be there for my daughter.” Managers who give this kind of support find that their people not only deliver but also stay longer — they’re proud of where they work.

People leave jobs, and it’s up to managers to design jobs that are too good to leave. Great bosses set up shields — they protect their employees from toxicity. They also open doors to meaningful tasks and learning opportunities — they enable their people to be energized by their projects, to perform at their best, and to move forward professionally without taking steps backward at home. When you have a manager who cares about your happiness and your success, your career and your life, you end up with a better job, and it’s hard to imagine working anywhere else.