Worked on the actualbudget/actual repository to enhance the reliability and accuracy of the mobile transaction preview. Addressed a critical issue where running balances were not displayed correctly by refactoring the balance calculation logic and leveraging React’s useMemo hook for improved performance and reduced unnecessary recomputation. Focused on front end development using TypeScript and React, ensuring that running balances now accurately reflect user settings in the mobile interface. Updated documentation and release notes to clearly communicate the bug fix. The work prioritized maintainability and data correctness, resulting in a more responsive and dependable mobile experience without introducing new user-facing features.