Featured Project
ECHealth Healthcare Booking System
Full-stack healthcare appointment booking platform mini-program within Octopus app, featuring React frontend and Spring Boot backend with AWS integration.
Role
Full-Stack Developer
Timeline
October 2025 - November 2025
Category
professional
5,277 lines of code
39 commits
Full-stack
AWS integrated
Overview
Built comprehensive healthcare booking system as a mini-program (webapp) within the Octopus app for ECHealth. Developed both React 19 frontend with TypeScript and Spring Boot backend, implementing appointment booking, cart management, checkout flow, and email notification system with AWS SES. Includes automatic database migrations, OAuth2 authentication with token refresh, and bilingual support (EN/ZH-HK).
What I Built
- •Built complete React 19 frontend with TypeScript (1,643 lines) featuring brand selection, product catalog, booking flow, and cart management
- •Developed Spring Boot 3.4 backend (3,634 lines) with RESTful APIs, OAuth2 + JWT authentication, and automatic token refresh on 401 errors
- •Implemented AWS SES email notification system with async processing, Thymeleaf templates, and dual notifications (customer + CS team)
- •Created automatic database schema migration system detecting and converting enum columns from smallint to varchar for API compatibility
- •Built zero-setup development environment with automatic data population seeding 4 healthcare brands and 30+ services on startup
- •Deployed to AWS infrastructure with S3 static hosting, CloudFront CDN, Lambda@Edge URL rewriting, and RDS PostgreSQL database
Key Achievements
- 5,277 lines of code (39 commits) in 5 days across frontend and backend
- Bilingual support (English/Traditional Chinese) with i18next and backend Accept-Language headers
- Fixed critical infinite loop bug causing thousands of API calls per second
- Zero-setup development with automatic schema migrations and data seeding
- Production-ready with comprehensive security (4 CVEs patched), error handling, and AWS deployment
Technologies Used
React 19TypeScriptJava 17Spring Boot 3.4PostgreSQLAWS SESAWS S3CloudFrontMaterial-UITailwind CSSi18nextOAuth2 + JWT
Tags
Full-StackReactSpring BootHealthcareAWSTypeScriptMini-Program