When Brynne McNulty '06 pitches her start-up to investors, she tells them about moving to Bogotá, Colombia, with her Colombian American husband in 2016 and struggling to find a place to live.

 The residential real estate market in Latin America, the Harvard Business School grads learned, was a mess.

 "The most common way to sell your home is to hang a giant poster with a phone number on a window or off a balcony," McNulty says. "The majority of homes are not listed online, anywhere. The listings players work more like Craigslist."

 There's no formal system of licensed brokers in Bogotá, she says. Figuring out a fair price for an older home is a challenge, because there's no public information about prior sales.

 "And this is the most significant financial decision that people will make in their lifetime!" McNulty says.

 McNulty had been interested in real estate finance ever since she was an undergraduate at Wharton and took a class on mortgages around the world. The class helped her understand how real estate can undergird people's financial stability. "I took that class and I thought, wow, I want to be able to have that kind of impact in the world," she says.

 After living and working for a few years in Bogotá, she teamed up with a friend, local entrepreneur Sebastian Noguera Escallón, to start a company they hoped would transform the experience of homebuyers and sellers—and of brokers, banks, and developers—throughout Spanish-speaking Latin America.

 They launched their company, Habi, in 2019 with an ambitious plan to transform the residential market across the continent. For their first product, they were going to be a market maker for "used" (not newly developed) homes. The plan called for Habi to buy older homes, renovate them, and sell them. It would streamline the process to help people sell their homes. Soon after, Habi would expand into other products and originate mortgages. Eventually, it would list homes online and offer free home evaluations.

 McNulty and Noguera Escallón decided to start by buying and selling homes in Bogotá. To do that, they needed better pricing data. So they hired a local data scientist and hit the streets.

 "We sent people, on foot, on a neighborhood-by-neighborhood basis, to collect every window listing," McNulty says. "And we took a photo of every single window listing, and we had a call center call every single window listing."

 The team then cross-checked listed prices with publicly available information, such as when the building was built and its square footage. It took five months for the company to understand the local market well enough to buy its first house.

Two years and two rounds of venture funding later, Habi expanded to Mexico City. The company now employs about 1,500 people and offers all the services McNulty and Noguera Escallón initially envisioned in more than 10 cities across Colombia and Mexico. It also offers some of its services in another five cities in those countries.

 Habi is now the largest buyer and seller of previously owned homes in Colombia and Mexico "by many orders of magnitude," McNulty says.

 Today, McNulty lives in Miami, a good base for traveling to Habi's Latin American offices and to meetings with U.S.-based venture capitalists and lenders. Her mother and mother-in-law also live in South Florida, an important consideration as McNulty and her husband (who also has a demanding job) have three children under age 5.

 Most days, McNulty says, she loves her busy life. "Almost every day I can't believe that I've found myself in this situation in which the company is where it is today, and I have this lovely, beautiful family that I'm very lucky to have," she says.

 But there are tough times, too. "It is definitely a roller-coaster," she says of running a start-up. "You are so deeply, emotionally tied to the success of the company"—and to the well-being of its employees.

 "If you make a decision that could put the company out of business, those people won't have jobs anymore," she says. "And that causes real stress."

 At the end of the day, McNulty says, Habi's mission energizes her.

 "When things are hard and things are exhausting, it's so easy to continue to be motivated to hire the best people in the market, to keep the team excited, when you know that what you're building changes lives and changes the financial future for families," McNulty says. "That's really cool."