WHO: Jain leads machine-learning efforts; Khilnani manages the file-conversion team; Williams directs platform engineering.

THINK OUTSIDE THE … : These three engineering superstars drive technologies—predictive analytics, business apps, data storage—that help push the file-sharing company into new areas. “It’s hard to see from a user’s perspective,” says Khilnani, “but there’s a lot of depth behind the scenes.”

BOX POPULI: When they’re not developing software, the trio is hard at work trying to crack another code: how to attract (and retain) more women in technical roles.

SOAPBOX CIRCUIT: Williams sponsors the Los Altos, Calif., company’s Women in Tech group, Khilnani organizes Girl Geek Dinners, and Jain participates in the annual Grace Hopper Celebration of Women in Computing. “We still have a lot to do,” says Jain, “but I’m not the only girl all of the time anymore.”

A version of this article appears in the November 1, 2015 issue of Fortune with the headline “Not boxed in.”