Building Card Sense as a side project

I've spent years building features for a credit card app. But understanding which card to use for what still trips people up — including people who work in fintech.

The gap

Cashback structures, foreign transaction fees, sign-up bonuses — most people don't optimise their spending because the information is fragmented and the mental overhead is too high. Card Sense is my attempt to fix that.

Shipping solo vs. shipping at scale

The contrast is stark. At Capital One, shipping a feature involves cyber review, accessibility audit, compliance sign-off, and a coordinated release across platforms. Card Sense ships when I push. Both approaches have taught me things the other couldn't.

What's next

Spending insights — patterns over time rather than just per-transaction categorisation. If you use Card Sense, I'd genuinely love to hear what would make it more useful.