Merchant payments app
A cross-platform mobile app for a UK FCA-authorised payment institution: it onboards merchants, then becomes the place they run the business day to day. I worked on it as a product engineer, on the app and the surfaces around it.
- iOS + AndroidOne cross-platform app
- MVP → productionOwned end to end
- FCA-authorisedacquiring (PSR 2017)
01Context
The client is an FCA-authorised payment institution: UK merchants get one provider for card acquiring and payments, and the mobile app is where they meet it. It is the onboarding tool first, then the app they open every day to see how the business is doing.
The product, its brand and its interface belong to the client, so this case study covers my role and the engineering problem rather than their screens.
02The challenge
Two jobs, one app. Onboarding to a regulated acquirer means identity and business verification and compliance steps that cannot be skipped, and every extra step is a chance to lose the sign-up. The same app then has to serve daily operators who want their numbers at a glance, not another form.
It also has to be trustworthy by construction: strong authentication, PCI-compliant handling of card data, and secure document storage, all on the phones a small business actually carries around.
03What I built
I worked as a product engineer on the cross-platform app (iOS and Android) and the surfaces around it, in React Native and TypeScript. The onboarding side takes a business from first launch to a verified, live account with clear state at every step. After onboarding, the same app turns into a management surface: performance, transactions, settlements, and notifications.
I owned the mobile platform end to end: architecture, state management, native module integration, testing, and the release cycle across App Store Connect and Google Play, including CI/CD, crash monitoring, and store review.
04Outcome
The app runs in production on iOS and Android inside an FCA-authorised acquiring platform, as the merchant's onboarding and daily-management tool.
I owned it from MVP to production and then through several years of releases and maintenance, and led a small team of engineers on it.
Client companies are not named here, and their logos and screens are not shown. That is by agreement between the parties: the work is mine to describe, the brand and the product are theirs. Everything above is the engineering problem and my part in it.