Divvy — Expense Splitting PWA

Highlights

• Built a full-stack expense-splitting PWA using React 18, TypeScript, Node.js, Express, and MongoDB with JWT + Google OAuth authentication and email verification flows.
• Engineered a smart debt-simplification algorithm reducing N-party group balances into minimum transactions, with real-time recalculation on every expense or settlement event.
• Implemented a multi-mode split engine (equal, percentage, exact) with lock-aware redistribution logic that auto-adjusts unlocked participants without overriding manually set values.
• Designed a token-based group invite system with expiry, role-based member controls, UPI deep-link settlement, and receipt image upload with per-expense participant breakdown views.
• Delivered full i18n support across 200+ keys in English and Hindi using react-i18next, alongside animated bottom sheets, skeleton loaders, onboarding tour, and mobile-first responsive UI.

Tech Stack