CashlyWise

Purpose

Help users build mindful financial habits through seamless transaction tracking, budget limits, debt tracking with repayments, and offline sync.

What it does

• Offline-first outbox synchronization
• Income, expense, and budget tracking
• Debts and loans tracker with partial repayments

Built with

• React Native
• Expo
• TypeScript
• Hono
• Turso
• SQLite

My role

Full-stack mobile and backend architecture spanning the Expo/React Native app, Hono REST API, offline SQLite outbox, and Turso database.

Technical implementation

• Engineered an offline-first SQLite outbox queue that automatically syncs pending transactions when connectivity restores.
• Built monthly category budget safeguards with real-time alert thresholds and notification summaries.
• Implemented debt and loan tracking supporting partial repayments, due date reminders, and dashboard balance updates.

Architecture & workflow

• React Native and Expo Router client with NativeWind styling and FlashList for high-performance ledger scrolling.
• Hono Node.js REST API with Better Auth managing Google OAuth sessions and authenticated data endpoints.
• Turso distributed LibSQL database managed through Drizzle ORM migrations paired with local device SQLite.

Challenges

• Managing seamless offline transaction creation and deterministic conflict resolution without losing user ledger entries.
• Ensuring secure authentication and token storage across native Android and iOS mobile environments.

Solutions

• Built an encrypted local queue with background synchronization and visual sync indicators.
• Paired Better Auth with Expo SecureStore and bearer token interceptors for tamper-proof session persistence.

Documented outcomes

• Delivered a comprehensive, production-grade personal finance application with instant offline entry, cloud sync, and bilingual support.