Last year, Tatiana Sorokina’s twin sister was struggling to figure out where she should do her medical residency. From the thousands of options, each with it’s own set of offerings and requirements, how could she know what really mattered? How could she even know what was available, much less what was good?

It was a nightmare, but Tatiana’s sister had something other soon-to-be med students didn’t: A data scientist for a twin. So in a move that might just qualify her for Best Sister of 2015, Tatiana created an algorithm that would help her sister sort through her many, many options.

When her sister got into med school, sanity intact, Tatiana brought the prototype to her colleague Louisy Raymond, a veteran marketer with years of experience a...