Cathy Engelbert is the CEO of Deloitte, a consulting firm that employs 85,000 professionals who serve over 80 percent of Fortune 500 companies.

She has been on Fortune's Most Powerful Women list for three years running; was ranked one of Crain's 50 Most Powerful Women in New York; and is in the top 100 on Glassdoor's 2018 list of highest-ranked CEOs, at number No. 65.

She's a powerhouse.

So when Engelbert talks about what makes her so productive (and respected), it's worth taking notes.

We live in a go, go go, do, do, do kind of culture. We've got endless to-do lists, constant notifications, and frequently operate in "always-on" kind of environments.

This can make it challenging to focus on the things that really matter.

Engelbert says her secret to being more productive has nothing to do with any of those things. It isn't about how much she can get do in what period of time, or her morning meditation routine, or micro-dosing the latest mind-pill.

Instead, as she told  Glassdoor, "To me, productivity is directly related to the personal relationships you are able to build."

Personal relationships. With her team, her clients, her fellow executives.

"Building a team that brings you solutions instead of challenges, listening to and collaborating with them--that ultimately prioritizes your focus on issues where you can have the most impact, not just scratch items off the to do list," she says.

In other words, by prioritizing the relationships--putting most of your time, attention, and resources into those, you know where to focus. You don't guess about what's important, or waste time on things that don't really matter, or try to come up with strategic directives from the top down that won't actually make an impact.

In other words, if you're investing your time in maintaining strong relationships with your top managers, and three of them have each brought up something similar, you know it's time to take a hard look at it.

Engelbert adds that when it comes to building relationships, authenticity is critical. It isn't enough to just listen; you've got to also express yourself, and you've got to do so in a genuine fashion:

"We live in a world where people can sense insincerity or corporate-speak from a mile away. Companies and leaders have to be authentic in tone, voice, and action. It's not just about 'saying the right thing' but talking about what matters most to your company and your people, and backing that up with action."

It's not just about the big meetings, either. It's the smaller conversations. It's the walk back to the elevator after the meeting, when you ask how it went for that person. It's checking in with a recent hire: "How's it going? Is there anything you need to do your job better or more efficiently? Anything you're finding issue with?"

It's seeking someone out to have a five-minute, in-person check-in instead of reaching out on Slack.

Yes, it will take more time. But it's a better investment of your time in the long run.

There's lots of advice out there on how to be more productive and successful. But it's good to really take in that a top-rated CEO on one of the most transparent platforms out there about work happiness says this is the most important thing to do:

"Prioritize people over tasks."

Correction: An earlier version of this article misstated Deloitte CEO Cathy Engelbert's rank on Glassdoor's 2018 list of top CEOs. She is No. 65.