Blockchain Payment Demo

About This Project

A full-stack decentralized payment system I built as a personal project. It enables merchants to accept USDC and USDT stablecoin payments across multiple EVM chains including Ethereum, Base, Arbitrum, Polygon, and Optimism. The backend uses a microservices architecture with separate payment and order services built with Koa.js and Prisma ORM on PostgreSQL. Payment verification is handled through three layers: direct transaction submission tracking, Alchemy Address Activity webhooks for real-time detection, and scheduled cron-based reconciliation as a safety net. The frontend is built with React, Wagmi, and ConnectKit for seamless wallet integration. Infrastructure is managed with Terraform, deployed on Google Cloud Run with Cloudflare Pages for the frontend.