Mobile App MVP

The problem

Zestful gave employees a virtual debit card with category-based spend controls for perks — Food & Drink, Wellness, Learning. It was web-only, and roughly 30% of card transactions were declining, half of them for insufficient funds. Support was flooded with “why did my card decline?”

Surveys told us why. People were out and about with no way to check a balance, forgot how much was left in each category, and some assumed the card worked like a gift card.

What I did

As employee #4 I owned product and design. I wrote three user stories — check my balance before I buy, know what the card covers, understand a decline immediately — and scoped the MVP to exactly that: category balances, eligible spend, and push notifications on declines. Nothing else.

We designed and shipped it in about two months on Stripe’s card-issuing APIs.

What happened

Within a month, ~60% of users had downloaded the app. The decline rate fell from ~30% to ~18%, and insufficient funds dropped from half of all declines to a third — just from making balance information available in the moment. Support volume fell with it.