Simple already had a strong fan base but was struggling to expand in the current financial climate. A glaring reason was simply that we only offered checking account services. Simple also has a feature called 'Goals' - it is our construct of envelope budgeting. So to continue making goals a great savings habits and benefit the users, we finally made the serious decision to provide interest through the guise of a “Special Goal” called the Savings Goal.
V1 included the BE technology to integrate a new account under a “Goal”, legal, and the one goal that we'd provide interest on to launch our first interest-bearing account. There were significant challenges that we had to address just by needing the savings account act like a “Goal”, this included how to visually communicate this to the user, to how the interest was deposited, to how it shapes our users' financial mental model in the app.
Challenges to workaround included account transparency (following the Wells Fargo debacle). This dictated a certain amount of information that we were required to display and the way accounts can mix-mash. Our options needed to be user-friendly but also compliant. Other headaches: since this goal is an account, it can receive ACH transfer, but normal Goals could not. Overall, lots of quirks and inner workings to smooth out.
We landed on the version that broke the user mental model of “Goals” the least - so the user did not need to reorient and kept the larger app concept of Safe-to-Spent/Goals/Expense less fragmented. This also kept our UX principle of being simple.