But before Wilson and Ben-Joseph built a company worth millions, they spent months traveling together through China, the Philippines, and Colombia. They got stranded, lost control of plans, and figured out how to navigate unfamiliar places with each other.

They say they didn’t set out to test their compatibility as business partners: They were just two engineers who were deciding what to do once they weren’t sure they wanted to become doctors. Wilson was a biomedical engineer who had been preparing for medical school—but decided to pursue consulting instead, before starting a data science firm. Ben-Joseph, meanwhile, was a bioengineer at MIT who was also preparing to attend medical school. The two eventually met in Boston through a Craigslist sublet—and so, with some time on their hands, decided to travel.

In hindsight, the trip was something closer to a cofounder’s “boot camp,”  Wilson, president and cofounder of Regard, told Fortune. 

“It was like extremely high-stress situations, very ambiguous,” he said. “You’re dropped into situations where you’ve lost a lot of control. Things are going sideways, and you see what a person’s really like when you travel together for months.”

“I would encourage every founder or would-be-co-founders to do exactly that—because it’s a blunt metaphor,” he continued. “But in many ways it’s like a marriage, right? You get started, you’re working together, and there’s no easy way out.”

The experience, he says, became the foundation for a partnership that eventually produced Regard, an AI healthcare company that analyzes medical records to help physicians identify diagnoses and other clinical information that might otherwise be missed. The company is now used across several hundred hospitals, according to Wilson.

Wilson isn’t arguing to take a 10-month trip with your colleagues—he’s saying out-of-work and unprepared chaos can be a good litmus test for whether you can succeed at building a business. If he was going to spend years building a business with someone, he had to give it a test run first.

“You got to really know this is the person,” he said. “Don’t look for the resume. Don’t check the boxes. [You’ve] got to spend some serious, serious time with the person. And ideally, in a place where it’s not smooth sailing. You want to see what it’s like when things go sideways, and for better and worse, we got plenty of that when we were traveling for those months.”

Their trips took them through China, including Hong Kong, Beijing, and Shanghai. They also traveled separately together through the Philippines and Colombia, creating what Wilson described as a “daisy chain” of trips.

According to Wilson, there were bad trains, power outages, remote towns, and situations where they had little money and no easy way out. He said those moments revealed something that ordinary work meetings could never.

“You really just get to know someone on a level that transcends the work,” Wilson said. “I know what they’re like at their best. I know what they’re like at their worst.”

He said he quickly learned that Ben-Joseph was “very cool under pressure.” The pair developed a shared assumption that when something went wrong, they would simply work it out.

“We have had so many highs and lows over the past eight, nine years,” he said, “and the highs are higher with someone who has a shared understanding of the world—who you really like to bond with, and you know really you know respect deeply—and the lows are like way less bitter. So to have that in someone that you’re building a company with, it’s magical.”