This blog content comes from an interview conducted on September 3, 2026. For more information or context, watch the full episode where you get your podcasts.
“I want to be Kimley-Horn only more so. Let’s aspire to be a better version of ourselves as we grow and evolve.” - Aaron Nathan, Chief Operating Officer, Kimley-Horn
An engineering firm with more than 11,000 people has made Fortune’s Best Places to Work list 19 times. How does it keep its culture intact while growing at that scale? On this episode of the AEC GrowthCast, host Greg Hart talks with Aaron Nathan, a professional engineer with more than 25 years at Kimley-Horn and, since 2024, its COO, about the principles behind the firm’s sustained growth and why he’d rather be thought of as a janitor than an executive.
1. Write down your values, then don’t change them
“Any time someone asks me about core principles, we have something we call our core values and core purpose that are really true to us. We actually documented them in 2000. And for context, I joined Kimley-Horn in 2001 when we were about a thousand employees. They weren’t written to be aspirational. They were a reflection of who we were at that time.”
They’ve held up for more than two decades: “If you think about all the things that have happened in the world since 2000, we haven’t changed one word in our core values and core purpose over 26 years. Our core purpose is a statement to provide an environment for our people to flourish. And that truly is a guiding light for a lot of things we do, whether we’re doing exceptionally well in the market or whether we’re struggling with something. We truly do look at that and say, how do we live up to our core purpose?”
On the Fortune recognition, he keeps perspective: “We’re very appreciative of the external recognition. But it’s definitely the outcome of a lot of things we do, not necessarily a goal.”
The things Fortune notices are small: “We have these things called teamwork awards. You can give anybody a $75 award for doing anything. There’s very little approval to those. These little cultural nuggets, to me, coming out of college, just feel like a normal part of our culture.”
2. Treat growth as the outcome, not the goal
“You start with why do we grow. Sometimes I’ll say, hey, we’re 11,500. That’s it. We’ve reached the number we were trying to get to. Is there some number? And I think there’s a realization that we ultimately fulfill our core purpose when we grow.”
Growth creates room for people: “How do you provide an environment for people to flourish? When you grow, you create opportunity for whether it’s the young professional to step into a new opportunity, the senior person to get to do something a little different, to serve a different client.”
But it has to be done carefully: “You want to right-size it. You’ve got to be cautious about erosion of culture along the way. And so how do you maintain it one person at a time? You can’t skip steps; you can’t integrate in bulk. When I started, and I walked in, another young professional who had been here a year helped me out with something. That needs to be the same experience in our 175 offices today.”
He also remembers to keep growth in its place: “We’re working on our business plan for 2027. We’ll have growth goals, but we have to remind ourselves that growth is the outcome, not the goal in and of itself. There are points in time where maybe we need to slow down the pace of growth in a particular area, a particular market, to make sure it’s happening in a healthy way.”
3. Organize around the people who serve clients, and keep competition outside the walls
“We’ve always been organized around practice. We’ve always been structured to support our practice builders. That model allows us to continue to scale.”
Nathan’s own role reflects that: “I feel like I’ve had the opportunity to move down on the org chart, not move up. I moved down because I’m there to support others. I joke with folks I work down in the basement sometimes of the firm, because the practice builders are the ones serving clients and doing things on the front line.”
The firm doesn’t hand out the practice builder title. It describes a mindset: “We actually have a term that we’ll use called the well-rounded practice builder, who have a high-level responsibility for the success of their team, for their clients: win work, produce work, produce it with quality, collect the invoice. They do all the things you need to do to run a business successfully. And we also acknowledge that nobody’s perfect at all those things. So how do we support people along the way in sort of running their own small business?”
Structure and ownership reinforce the culture: “We’re one profit center as a firm. So you’re encouraged to share resources and partner with the practice builder down the hall versus compete with the practice builder down the hall. We’re also privately held by active employees. Roughly 80% of our owners are practice builders as well.”
Nathan cites a favorite quote from investor Charlie Munger: “‘Show me the incentive, and I’ll show you the outcome.’ So when the incentive is to be a better version of Kimley-Horn, we have plenty of competition outside our walls. So we try to cut it down inside our walls.”
4. Develop leaders in front of clients, and know when to hug and when to shove
“We are proud of giving responsibilities early. We definitely see the most leadership opportunities with our clients, in practice, in projects. So encouraging young professionals, ‘Hey, go to that client meeting. Go to that planning and zoning commission meeting.’ Even if you’re just there to take notes, we think that becomes the ground for development, not in conference rooms, internal meetings. Serving clients is the training ground for the vast, vast majority of our leaders.”
He tells a story from his own early career: "My supervisor wasn’t the best note taker. He’d come back, and the guidance wasn’t clear. And I said, ‘I’m going to the next meeting to take notes, because your notes aren’t good.’ A week or two later, the client calls the office and can’t get a hold of my supervisor. ‘Hey, Aaron, you were there. Can you help with this?’ I didn’t even understand what they were asking for. And my supervisor says, ‘Sounds like you need to figure it out then. He called you.’ I was probably 24 years old.”
A young colleague in Texas gave him a phrase for how to support emerging leaders: “He said, ‘Sometimes I need a shove. You need to push me out there and make me uncomfortable. But there’s other times, can you come give me a hug? Because it’s a little scary out there by myself.’ I’ve more now adopted this hug and shove mindset of knowing when to push somebody and knowing when to say, ‘Hey, I’ll help you.’ You’ve got to know your folks, you’ve got to know your team, you’ve got to be a strong leader to know when to push. So that’s a delicate balance.”
Titles don’t gate leadership at Kimley-Horn: “We don’t put titles on business cards. We haven’t for decades. Most people’s email signature doesn’t have a title on it. We empower practice builders to serve their clients. The people we identify for titles with leader in the title, they come out of, ‘Hey, you were pretty good over here, and you’ve shown some acumen for these other things. Maybe we’ll grab you.’ The noteworthy thing about it is it becomes a bigger ground of people from which to pull for leadership.”
5. Listen to the front line, not just the dashboards
Asked which operational metric he checks every week, Nathan shares an analogy from the firm’s president: “What instrument in the orchestra do you listen to? I think if you overfocus on a singular metric, you’re kind of indicating to your teams that the other ones aren’t as critical. There’s profitability and backlog and workload, retention, all sorts of stuff you can dive into. I have a lot of dashboards. But you’ve got to understand the story behind the metric, which requires you to listen to your practice builders.”
“We have tremendous tools, but I work to connect with what we’re hearing from the quote-unquote front lines, because that’s where the magic is. I watch the news, but my intel from practice builders, that’s the real story about what’s happening.”
Dashboards show the past, and leaders need a view of what’s next: “I absolutely look at those things, but that’s a glance. That’s an awareness. It’s really easy to look backwards on performance. It’s really hard to see the future. And so that’s what you’re really trying to study: what dials do we need to turn differently now?”
6. Build depth, because clients want availability
Kimley-Horn has been asking clients for feedback for decades: “We’ve run a quality call program for going back to the nineties. It’s 30 years of asking clients a set of questions. ‘How are we doing? How can we serve you better? What should we be aware of?’ We ask thousands of clients each year what’s going on.”
The answer is consistent: “Regardless of market sector, regardless of client type, availability and responsiveness is so critical. Clients want to know the status of their project, the data, the files, the report, the map, the chart, at their fingertips. It puts pressure on our teams to be available at all times, which is impossible. If you’re serving multiple clients, you can’t be available to every client every moment all the time. And that’s just not healthy. So it’s impossible for one person to be a backstop for a project.”
His response is to show clients the strength of the whole team: “Our clients, I think, are best served when they see the depth of our team, and they know who to go to for that availability and responsiveness. Certainly, if they desire to have one point of contact, we can navigate, but you realize when you call that one person, they’re just going to reach out to the other. How can you know everything about an entire program?”
That depth helps his team, too: “It’s nice to be able to either check out for the day or go on vacation and know that the organization can still function. My name is not on the door, and I’m okay with that.”
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