“Our family would have gone bankrupt without Medicaid,” she said. “It saved us.”

The Medicaid system covers millions of working families, older people, children and people with disabilities. In fact, 40 percent of Medicaid spending goes to the disabled. Half of long-term care in America, mainly for older people, is through Medicaid. And nearly half of the children born in the United States are in the Medicaid system.

The trouble with traditional health data warehouses, specialists say, is that they resemble digital vaults. It is difficult and time-consuming to get information in or out, and only people with specialized skills can use them.

But the new cloud-based technology, using internet-era software, is flexible and interactive. It opens the door to real-time monitoring of emerging disease clusters, billing patterns and program effects. For example, did the percentage of low birth-weight babies decline after a Medicaid program was put in place? If so, how much?

“This kind of data can help move health care policy from a partisan ideological debate to one informed by knowing who the people affected are and what will likely happen to Medicaid recipients,” said Drew Altman, president of the Henry J. Kaiser Family Foundation, a nonprofit health policy research organization.

Though young, Ms. Kim has spent years learning hard-earned lessons about health care. At Google, she was a product manager on Google Health, a failed effort to attract millions of people to use its free, online personal health records.

“Health care is hard, and humility is important,” Ms. Kim said. “You can’t just put technology on something and assume it’s going to work. You really have to understand the ecosystem in health care.”