You might not expect the nation’s leading mobile bank, with north of 31 million users, to be in a hurry to build a digital bank under a new brand, but that’s just what JPMorgan Chase did last October with Finn.

Clayton Christensen’s famous “innovator’s dilemma” notes that it is difficult for incumbents to launch new products that might detract from their core businesses — hence Kodak built the first digital camera but didn’t sell it for fear of cannibalizing film sales. Chase does not intend for Finn to convert existing Chase mobile customers, according to Melissa Feldsher, who heads up the Finn program. Rather, Finn is a new way to enter untapped markets (Finn launched in St. Louis, just such a market) that is cheaper and more efficient than building out a brick and mortar network, but may require more skillful marketing.

Finn is quite different from Chase’s standard app. Among several new financial management features, the app allows users to tag transactions with happy, sad, or neutral emojis (hellooo, student loan payment!)

On this episode of Fintech Unfiltered, Feldsher discusses how Finn was built, from the team to the tech stack, and how the project fits into the agenda of the nation’s largest bank.