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JM
Case Study

Data-Driven Expense Tracking & Personal Finance Platform

The Challenge

Users struggled with manual and scattered tracking of multiple bank accounts. Spotty cellular network connections led to data loss during transaction entry, and there was no way to view real-time forex conversions for international spend.

Technical Stack

React NativeExpoSupabasePostgreSQLExchangeRate API

The Solution: Secure, Offline-First Sync Architecture

I developed a cross-platform React Native dashboard that queues mutations locally and synchronizes transactions once a connection is detected, ensuring reliable personal expense tracking.

Offline Caching & Queue

Uses SQLite for local database caching, automatically syncing queued edits with Supabase Postgres once connection is restored.

Real-Time Exchange Rates

Integrates forex exchange rate API endpoints to normalize multi-currency transactions under a primary billing currency.

Interactive Analytics

Aggregates spend metrics to render budget indicators and transaction progress rings for fast financial evaluation.

Category Budgets

Maintains custom budgets per category and warns users as they approach transaction limits using reactive charts.

The Impact

  • Budget Optimization: Helped active users identify unnecessary subscriptions and spend leaks, leading to a average 30% saving.
  • Robust Persistence: Achieved 100% data preservation during network drops with local-first database buffers.
  • Fast Response: Reduced transaction entry overhead to sub-second load speeds, boosting application reuse.