React Native Case Study: Take Home Pay
Take Home Pay helps UK professionals calculate net income, compare offers, and plan negotiations in seconds. I led the React Native build and release cycle for iOS and Android, focusing on accuracy and offline performance.
User Needs
- Instant gross-to-net and net-to-gross conversions across annual, monthly, weekly, daily, and hourly views.
- Support for nuanced tax rules including Scottish bands, student loans, pensions, and bonuses.
- A single codebase that delivers consistent experiences on both app stores.
Engineering Approach
- Domain modelling: Partnered with tax specialists to encode PAYE, NI, and pension logic into reusable calculation modules with extensive unit coverage.
- State management: Leveraged React Native with TypeScript, React Navigation, and Redux Toolkit to keep UI state predictable as users toggle scenarios.
- Offline storage: Implemented encrypted local persistence so saved scenarios remain available without connectivity.
- Visualisation: Combined native chart components with theming support (including automatic dark mode) for quick comprehension.
Impact
- Users rely on the app during job searches and annual reviews, citing the speed and accuracy of real-time updates.
- Cross-platform release cadence dropped from weeks to hours thanks to shared CI/CD scripts and Fastlane automation.
- Ratings highlight the clarity of the breakdown and the ability to save personalised calculations.
