The phone call that changed Jini Kim’s life came at 2 a.m. in November 2013. The White House needed the former Google product manager’s help with Healthcare.gov, which had been meant to help people buy health insurance but was riddled with embarrassing glitches. She hopped on a plane that day and worked marathon hours to fix the site, giving up Thanksgiving, Christmas, and her birthday. By the time she left, six months later, the site had enrolled eight million people in insurance plans—and Kim had gained insight that would be crucial for her own health-care analytics company, NunaHealth.

Founded in 2010, Nuna helps companies shape their health-insurance benefits and wellness programs. It analyzes anonymized data about employees’ behavior to determine the answers to questions such as “Are there differences in how people in certain demographic groups seek health care?” or “Can more generous health insurance help improve the productivity of someone with a seriously ill family member?”

Before she bailed out Healthcare.gov, Kim viewed the government the way many people in Silicon Valley do: as a hindrance to innovation.Accordingly, Nuna originally sold its services only to corporations. But during her stint working for the Obama administration, she saw the enormous potential the government had to effect change. “You can touch millions of people so easily,” says Kim, recalling a day at a Healthcare.gov call center when she overheard desperate people crying because they were unable to sign up for insurance.

Upon her return to San Francisco, Kim expanded Nuna so that it now also works with local, state, and national governments. For example, the company helps the Centers for Medicare and Medicaid Services find patterns in their vast amounts of data.

For Kim, reforming health care is not a theoretical issue. Her 33-year-old brother, Kimong,has severe autism. She has been involved in his care since she was nine years old and had to sign him up for Medicaid on behalf of her immigrant parents. She still lives at home to help out. Nuna’s meeting rooms are named after Kimong’s favorite Sesame Street characters, and she brings him to work regularly to give her parents a break. The name “Nuna” comes from the Korean word for “big sister,” one of three words he knows.

—Yukari Iwatani Kane