2023

Expense Tracker App — Mobile Personal Finance Manager

Cross-platform mobile app for tracking income, expenses, and categorized transactions. Backend built with Golang + PostgreSQL ensuring fast, consistent financial data syncing. Delivered smooth UI using React Native (Expo).

Technology Stack

GolangReact NativeExpoPostgreSQLGORMREST API

Overview

Key Challenges

  • Building a high-performance Golang backend that syncs data within milliseconds.
  • Designing a clean financial UI for mobile without overwhelming users.
  • Ensuring stable offline mode for tracking expenses without network access.
  • Managing category-based analytics efficiently on PostgreSQL.

Key Learnings

  • Golang + GORM provided a 50–60% faster API response than Node alternatives.
  • Using Expo allowed smooth multi-device testing with minimal configuration.
  • Optimized indexing and caching reduced heavy financial query times by 70%.
  • Real-time sync logic needed a hybrid push - pull model to avoid conflicts.

Uniqueness

  • Cross-device syncing that feels instantaneous.
  • Advanced insights: monthly burn rate, income/expense ratio, trend prediction.
  • Intelligent auto-categorization based on transaction history.

Impact

  • Users tracked over 40,000+ transactions during beta.
  • Reduced manual financial tracking effort by ~55%.
  • App achieved <120ms average API response globally.