What Building Fintech Apps Taught Me About Writing Better Code

Fintech is unforgiving. You're dealing with real money and real users. A glitch in a social app is a bad UX moment. A glitch in a payment flow means someone loses money or trust, sometimes both. After spending years building across fintech and crypto products, here's what that environment actually drilled into me. You start thinking about failure first In most apps you can afford to be a little optimistic. In fintech you can't. What happens if the network drops mid-transaction? What if the user hits the button twice? What if the third party API returns a 200 with a broken body? You stop treating edge cases as afterthoughts. That habit sticks with you even when you move to lower stakes projects. Types stop being optional When you're moving money around, a string where a number should be is not something you push to fix later. I became a much more deliberate TypeScript user building fintech than I ever was before. Strict mode on, no shortcuts, model your data properly from day one. The c