Demand for data scientists is growing, driven by companies and government agencies that are flooded with data and struggling to make sense of it.

But what exactly do data scientists do? Wall Street Journal reporter Deborah Gage spoke with one—Ram Narasimhan, who works at General Electric Co. ’s GE Digital in San Ramon, Calif.—to shed some light on the profession.

A former managing director at United Airlines in Chicago, Dr. Narasimhan moved to the Bay Area in 2012 and was among the first data scientists hired by GE. He has a doctorate in operations research and industrial engineering from the State University of New York at Buffalo, but he says the most important quality in his job and for any data scientist is curiosity. Here are edited excerpts of the conversation.

Starting at the airport

WSJ: What led you to become a data scientist?

DR. NARASIMHAN: I was an engineer by training and was drawn to math and applied math in general—the math you use for puzzles. I did my master’s and Ph.D. in applied math and operations research. [These skills are] really useful for airlines, and I got hired at United and spent about 12 years there. My colleagues and I would decide where should we fly, how often, how big or small a plane, how many people should we carry, how do we compete, what are other airlines doing, how much can we charge and network optimization—how to build a schedule month after month.