SaaS · web app rebuild · under NDA / NDA project
Rebuilding a finance subscription app around fewer manual errors
01 / Context
The existing tool handled financial subscriptions but leaned on heavy manual data entry, which is exactly where money-handling software can't afford mistakes. The client wanted a modern, type-safe rebuild that made errors harder to make in the first place.
02 / The challenge
In finance software, a mistyped number isn't a cosmetic bug — it's a real-world problem. The rebuild had to reduce manual-input errors by design, stay fully type-safe end to end, and be accessible, while keeping the data model clean as it grew.
03 / Scope
What I did
- 01Owned frontend architecture for the rebuilt application.
- 02Designed data handling and UX specifically to reduce manual-input errors.
- 03Built an accessible interface that met real usability requirements.
- 04Added end-to-end testing to protect critical financial flows.
04 / Key decisions
Key decisions
- 01
End-to-end type safety with TypeScript, tRPC and Prisma
A typed path from database to UI means whole categories of data-entry and integration bugs are caught at build time, before they ever touch a customer's finances.
- 02
UX designed to prevent mistakes, not just catch them
Inputs, validation and flow were shaped around how people actually make errors, reducing the chance of bad data entering the system at all.
- 03
e2e tests on the flows that matter
Critical financial paths are covered by automated end-to-end tests, so changes ship without silently breaking the parts that handle money.
05 / Evidence
Results
- 01
A rebuilt, type-safe application with a data model and UX aimed squarely at fewer manual-input errors.
- 02
An accessible interface built to real usability standards.
- 03
Automated end-to-end coverage protecting the critical financial flows on every change.
Stack
- Next.js
- React
- TypeScript
- tRPC
- Prisma
- shadcn/ui
Services used
Related problems solved
My team wastes hours on manual work — how do I fix it?
As a business grows, the busywork grows with it: chasing leads, copying data between tools, sending the same emails, building the same reports. It feels normal, but you're paying salaries for work software should do.
I built an app with AI, but it's not ready for real users
AI coding tools get you to a working demo fast — then stall at exactly the parts that make a real product: secure payments, correct data, access control, and code you can keep building on. That's normal, and it's fixable without starting over.
The EAA accessibility deadline is here — is my website at risk?
The European Accessibility Act is now enforceable. If your site sells products or digital services to EU consumers, accessibility is no longer only a UX improvement — it is a compliance and business risk. The fix is not an overlay widget. It is accessible code, forms, navigation and content.
Have a similar project? Tell me what you're trying to build and I'll reply within 24 hours.