Paytm Payment System

Transactional peer-to-peer wallet

Full stack · Data integrity

A full-stack wallet for account creation, balance management, recipient discovery, and peer-to-peer transfers, with consistency at the center of money movement.

Design decisions

  • Protected account operations with JWT authentication and validated API payloads using Zod.
  • Used MongoDB sessions so sender debits and recipient credits commit atomically or roll back together.
  • Built searchable recipient discovery and a focused React transfer experience.

Technologies

  • React
  • JavaScript
  • Express
  • MongoDB
  • JWT
  • Zod

Source and documentation