How This Introvert Founder Became a Billion-Dollar Leader The key is compassion and energy.

Paul English sold Kayak to Priceline in 2012 for $1.8 billion. Now he is reentering the industry with Lola, a mobile app that combines AI with human travel agents to plan and book trips. And at both companies, he says, the key to success is the people he hires.

By texting with Lola agents, users can book hotels and flights, get restaurant recommendations and get help with itinerary planning. Were you a fan of travel agents back in the day?
Really back in the day, I used AAA. But I've also used a cruise travel agent, Wayland Travel for a safari, and, last year, American Express' concierge service in Japan. The trip to Tokyo was motivated by the documentary Jiro Dreams of Sushi. I was obsessed with it -- not because of the sushi, but because of this whole idea of what happens when a human being commits their life to perfection. Immediately after seeing the film, I got a couple of friends to go with me. One said she could get us a reservation at Sukiyabashi Jiro. Guaranteed. But at the last minute, her attempt fell through. So I called American Express and asked, "What's the best sushi restaurant in Tokyo?" They gave us a really unique recommendation that I never would have discovered on my own.

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How do you vet Lola's agents for that level of knowledge?
We have one woman who has been to every island in the Caribbean. When we get a Caribbean question, it's delegated to her. But if a question is too exotic for us, we advise our agents to be transparent. They might say, "I haven't been there before, but I can do a ton of research for you."

You identify as an introvert. How did you learn to be extroverted for work? Do you have to flip a switch in your brain?
I have 50 people in my company. Sometimes it's comfortable for me to sit in front of my computer and do email and Slack all day. But if that's literally all I do, it's sucking energy out of the room. People want to engage with me. I need to force myself to get up. It's a lot easier to transmit energy face-to-face than to transmit it electronically. I always keep my calendar open for breakfast, lunch and dinner. So at the last minute, I can just grab a few people I haven't seen in a while. Sometimes we have an agenda, but mostly it's just socializing, which is really important. There's efficiency to Slack and email, but without that human connection, it goes flat.

Much of your work goes back to this "human" element. At Kayak, you made your coders field phone calls for customer service issues. How come?
We're doing it at Lola as well. Only humans can have compassion. If you don't put them on the line together, you build layers of buffers between customers and engineers: customer support managers, product managers, designers, quality assurance engineers, engineering managers … By that point, the customer is so far removed from the engineer, the engineer has no compassion for the customer. By forcing the engineers to talk directly to the customers, they can design software to better address their problems.

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What are some other lessons you learned at Kayak that helped you with Lola?
The most important thing any entrepreneur can do is focus on the team. When I interview people, there are two things I look for. One is their GSD -- "get shit done" -- score. Do they have technical chops? The other 50 percent is: Are they energy amplifiers? Are they someone whom people enjoy being around? A lot of what I focused on at Kayak and what I'm focusing even more so on at Lola is playing the role of coach or organizational psychologist. I observe interactions, debug them and make sure we're set up for success.

What is your debugging strategy?
If I have two people who don't work well together and I just separate them, I've lost the ability for those people to give each other positive energy. So when something is dysfunctional, I talk to each person individually and then bring them together and say, "You're both extremely valued here, but you're not clicking, and I want to know what we need to do." Sometimes it's just a matter of being open and naming a problem.

That's very hands-on. Many managers hate dealing with personnel issues. But you obviously see it differently: Without these one-on-ones working, the whole company won't work.
Yeah, and it won't work well. I'm not interested in running a "successful" company, I'm interested in running an exciting company where people love their job.

You once hired a guy who'd earned an Olympic medal in rowing. You said, "This guy is hard-core, and I bet that translates." In that instance, you were right. Have you ever been wrong?
I've made the mistake of hiring someone whose style is so radically different from the team that it just didn't work. So the trick there is, I want diversity of style, but not too much diversity. There's a fine line.

You've talked about having bipolar disorder and your own hypomania and OCD tendencies. Do you become fixated on prospective hires?
My friends call it my pedestal complex. When I meet somebody who has a skill I don't have, I put them on a pedestal and worship them. And my friends are like, "Oh, God, here he goes again." I probably fall a little in love with everyone, in some way. But I've seen this movie enough times to know how it's going to play out, so I try to manage my own expectations. Like, there's a guy I just hired who is developing the user interface of the next version of Lola, and he's unbelievably strong. I'm trying to temper myself so I don't focus too much on him, because what if he disappoints me, like, a month from now and he's not as fast a coder as I think he is? I'm attracted to shiny new objects.

In Tracy Kidder's new biography of you, A Truck Full of Money: One Man's Quest to Recover from Great Success, he explores the idea of whether your manic spells are responsible for your entrepreneurial confidence, or whether you succeed despite them. What do you think?
They definitely played a role. There's this romantic notion about the intersection of art and mental illness. But I do a lot of work with homelessness in Boston, and there are a lot of bipolar and schizophrenic people on the streets -- and let me tell you, it's not very romantic. Mental illness can be very cruel. But if you're just touched with some type of mental illness and it makes you look at the world differently than most people and you happen to be creative and/or bright, it can be a wonderful thing. My manic phases last weeks and sometimes months. I have enormous energy, I get by with little sleep, I'm always excited and I'm always excitable. I can lead a team when I have that kind of manic energy. So in that sense, it's useful.

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Philanthropy has been important to you throughout your career. But a lot of entrepreneurs, especially those who are just getting started, pour every penny back into their business. At what point should people start thinking about others?
If I could have only one word on my tombstone, I'd want it to say "kindness." I want to be known as someone who cares about other people. Maybe I give to a particular 501(c)(3), or organize a group function at a food bank, or I'm kind to an old lady I meet on a bus. All of us need to be thinking about kindness. One, because it's the right thing to do, and two, if you're kind and you care when other people are in pain, it's going to give you really good skills as an entrepreneur. Successful entrepreneurs invent services that make things easier for people.

You've taught classes on entrepreneurship at MIT and elsewhere. If your students learned just one thing from you, what would you want it to be?
If I had a class of 50 students and wanted to predict by the end of the semester which one would create a billion-dollar company, I think it would be the kid who can energize a team of five. So, my one lesson is: Can you energize a small team and lead them and listen to them and care about them and motivate them and get them to work out disagreements and get them unified in one direction? I believe that is a skill that can be learned.