Lir Chen

Additional Screenshots

Project Overview

This project demonstrates a production-ready AWS infrastructure with complete CI/CD pipeline, comprehensive monitoring, and GitOps deployment strategy. Built with infrastructure-as-code principles using Terraform and deployed to AWS EKS cluster.

Key Features

• Production-Ready AWS Infrastructure: Complete EKS cluster with PostgreSQL RDS and ElastiCache Redis
• Multi-Worker Node Setup: Proper resource allocation with auto-scaling capabilities
• GitOps Deployment: ArgoCD for automated sync, rollback, and deployment management
• Comprehensive Monitoring: Real-time cluster metrics with Grafana dashboards and Prometheus
• Status Page Integration: Public status monitoring for all infrastructure components
• Security & Networking: VPC with public/private subnets, NAT Gateway, Application Load Balancer, and Network Load Balancer
• Infrastructure as Code: Complete Terraform modules for reproducible deployments
• Helm Charts: Kubernetes package management for easy deployment

Technologies Used

• AWS (EKS, EC2, RDS, ElastiCache, VPC, S3, ECR, Secrets Manager, Load Balancers)
• Terraform for infrastructure provisioning
• Kubernetes with Helm for container orchestration
• ArgoCD for GitOps deployment
• Prometheus & Grafana for monitoring and alerting
• Docker for containerization
• GitHub Actions for CI/CD

Technical Achievements

• Designed and implemented secure VPC architecture with proper subnet isolation
• Configured auto-scaling for optimal resource utilization
• Set up comprehensive monitoring with custom Grafana dashboards
• Implemented GitOps workflow for version-controlled infrastructure changes
• Created reusable Terraform modules for infrastructure components

Project Overview

FlavorWorld is a comprehensive cross-platform social networking application built for recipe enthusiasts. Available on both mobile (React Native) and web (React) platforms. Features include real-time messaging, advanced group management, social interactions, and a comprehensive recipe system with video support.

📱 Mobile App Demo

🖥️ Web Application Screenshots

🆕 What's New in Web Version

• Enhanced Desktop Experience: Glass-morphism design with optimized layouts for large screens
• Video Upload Support: Share cooking videos up to 60 seconds alongside images
• Advanced Admin Dashboard: Complete group management with role promotion/demotion and member controls
• Recipe Sharing in Chats: Share recipes directly in conversations with rich previews
• Comprehensive Notification Center: Centralized hub for all activity alerts with real-time updates
• Optimistic UI Updates: Instant feedback on likes and interactions without server wait
• Professional Security: Cascade deletion, XSS protection, MongoDB injection prevention

🔥 Core Features (Both Platforms)

• Cross-Platform Development: React Native for mobile + React with Vite for web
• Microservices Backend: API Gateway with specialized services (Auth, User, Recipe, Group, Chat)
• Real-time Communication: Socket.IO for instant messaging, typing indicators, and read receipts
• Advanced Social Features: Follow system, groups, likes, comments, personalized feed algorithm
• Recipe Management: Create, edit, delete recipes with images/videos, 16 cuisines, 10 dietary tags
• Group Communities: Create public/private cooking groups with admin controls and post approval workflows
• Smart Notifications: Real-time push notifications for likes, comments, follows, group activities
• Search & Discovery: Find users, recipes, groups with AI-powered suggested content

Technologies Used

• Mobile: React Native & Expo for cross-platform development
• Web: React 18 + Vite for modern web experience
• Backend: Node.js & Express with microservices architecture
• Real-time: Socket.IO for live features
• Database: MongoDB with optimized schemas for social interactions
• Authentication: JWT with bcrypt password hashing
• File Upload: Multer for images and videos with base64 encoding
• Styling: Modern CSS with glass-morphism effects and custom properties

Technical Achievements

• Built cross-platform solution serving both mobile and web users
• Implemented microservices architecture with API gateway pattern
• Designed real-time chat with Socket.IO including typing indicators and online status
• Created scalable MongoDB schemas for complex social networking features
• Developed responsive UI components with glass-morphism design system
• Integrated comprehensive notification system with real-time updates
• Implemented advanced group management with three-tier permission system
• Built recipe sharing feature with rich previews in chat conversations

Project Overview

FitFlow is a full-stack fitness tracking platform that helps users monitor their nutrition, workouts, progress photos, and fitness goals with advanced analytics and an AI-powered coach. Built with modern web technologies and containerized with Docker for seamless deployment.

Core Features

• Dashboard Overview: Real-time fitness summary with key metrics including weekly workouts, daily calories, current weight & BMI, and active streak
• Workout Tracking: Log exercises with duration, difficulty levels, and comprehensive workout history with date filtering (Today/Week/Month/Year)
• Nutrition Tracker: Track daily meals by type (Breakfast, Lunch, Dinner, Snack) with complete macronutrient breakdown (protein, carbs, fats) and visual charts
• Progress Gallery: Upload and visualize transformation photos over time to track your fitness journey
• Goals Management: Set measurable fitness milestones with visual progress bars and celebrate achievements
• Analytics & Stats: 4 interactive charts showing workout frequency, calorie intake trends, macros breakdown, and duration patterns
• BMR/TDEE Calculator: Calculate daily calorie needs based on personal metrics with calculation history
• Nutrition Trivia: Interactive quiz game to test and improve your nutrition knowledge
• AI Fitness Coach: Get personalized fitness and nutrition advice 24/7 powered by Mistral AI
• Profile Management: Complete user profile with the ability to update personal info, fitness goals, and change password securely

Screenshots Gallery

Tech Stack

• Frontend: React 18 with Vite, Recharts for data visualization, Lucide React icons, Modern CSS3 with glassmorphism design
• Backend: Node.js with Express.js, MongoDB with Mongoose ODM, JWT authentication, Bcrypt password hashing, Mistral AI integration
• DevOps: Docker & Docker Compose, Nginx reverse proxy, Multi-stage builds for optimization
• Testing: Jest & Supertest with 90+ comprehensive tests covering all API endpoints
• File Handling: Multer for progress photo uploads with persistent storage

Technical Achievements

• Comprehensive Testing: 90 tests across 10 test suites covering authentication, CRUD operations, analytics, edge cases, and error handling
• RESTful API Architecture: Well-structured API with 11 dedicated controllers for different features
• AI Integration: Mistral AI-powered coach providing personalized fitness advice with natural language processing
• Advanced Analytics: Real-time data visualization with filtering by Today/Week/Month/Year across all tracking features
• Docker Containerization: Complete Docker Compose setup with health checks, volume persistence, and optimized multi-stage builds
• Security: JWT-based authentication, bcrypt password hashing, secure password requirements (8+ chars, uppercase, lowercase, number, special char)
• Responsive Design: Mobile-first approach ensuring perfect functionality on all device sizes
• User Experience: Intuitive interface with modal-based editing, real-time feedback, and smooth animations

API Endpoints

Complete RESTful API with endpoints for:

• Authentication (register, login)
• User management (profile, stats, password change)
• Workouts (CRUD with period filtering)
• Nutrition tracking (meals CRUD with date filtering)
• Goals management (CRUD with progress tracking)
• Analytics (workout stats, nutrition stats, dashboard overview)
• Progress photos (upload, retrieve, delete)
• Trivia game (questions, answers, statistics)
• Calculator (BMR/TDEE calculation with history)

Application Screenshots

Project Overview

A production-ready authentication system with React frontend, Node.js backend, and event-driven architecture. Features JWT authentication with refresh tokens, distributed TiDB database, real-time change data capture (TiCDC), Kafka event streaming, and comprehensive Swagger API documentation. Fully containerized with Docker Compose for one-command deployment.

🎯 Try the Demo

Key Features

• JWT Authentication: Access tokens with refresh token mechanism for secure sessions
• Password Security: bcrypt hashing with 12 rounds and strong password requirements
• Rate Limiting: Protection on authentication endpoints (10 requests/min)
• TiDB Database: Distributed SQL database with TiKV and PD components
• Change Data Capture: TiCDC streaming database changes to Kafka in real-time
• Event Streaming: Kafka consumer processing user activities and database changes
• API Documentation: Interactive Swagger/OpenAPI docs at /api-docs endpoint
• Docker Deployment: Complete orchestration with docker-compose (one-command startup)
• Professional Logging: Structured logging with log4js for debugging and monitoring
• Security: CORS protection, input validation, SQL injection prevention

Tech Stack

• Frontend: React with React Router and Context API for state management
• Backend: Node.js, Express, JWT authentication, bcrypt password hashing
• Database: TiDB (distributed SQL), TiKV (storage engine), PD (placement driver)
• CDC & Messaging: TiCDC for change data capture, Kafka with Zookeeper for event streaming
• API Documentation: Swagger/OpenAPI for interactive API documentation
• DevOps: Docker & Docker Compose with multi-service orchestration
• Logging: log4js for structured application logs
• Security: CORS, rate limiting, input validation, SQL injection protection

Technical Achievements

• Event-Driven Architecture: Built microservices with Kafka for asynchronous event processing
• Database Streaming: Integrated TiCDC to capture and stream all database changes to Kafka topics
• One-Command Deployment: Complete Docker Compose setup initializing 8+ services automatically
• API Documentation: Comprehensive Swagger documentation with interactive testing interface
• Token Management: Implemented refresh token rotation for secure long-lived sessions
• Rate Limiting: Protected authentication endpoints with intelligent rate limiting (100 req/15min general, 10 req/min auth)
• Error Handling: Comprehensive error handling with meaningful error messages and proper HTTP status codes
• Production Ready: Complete with health checks, logging, monitoring, and security best practices

API Endpoints

• POST /api/auth/register: Create new user account with validation
• POST /api/auth/login: Authenticate and receive access + refresh tokens
• POST /api/auth/refresh: Get new access token using refresh token
• POST /api/auth/logout: Invalidate current session
• GET /api/auth/validate: Verify token validity
• GET /api/users: List all users (protected route)
• GET /api/users/:id: Get specific user details (protected route)
• GET /health: Application health check endpoint
• GET /api-docs: Interactive Swagger API documentation

📚 Full interactive documentation available at /api-docs endpoint

Project Overview

A comprehensive AWS resource management tool featuring both CLI and GUI interfaces. Built with boto3 for programmatic AWS access, managing EC2 instances, S3 buckets, and Route53 DNS records with enforced IAM policies.

Key Features

• Python CLI: Command-line interface for AWS resource provisioning
• GUI Application: User-friendly graphical interface for simplified management
• Multi-Service Support: Manage EC2, S3, and Route53 resources
• IAM Policy Enforcement: Automated security policies and permissions
• Automated Tagging: Convention-based resource tagging for organization
• Cost Optimization: Features for monitoring and reducing AWS costs
• Resource Monitoring: Track resource usage and status
• Batch Operations: Perform actions on multiple resources simultaneously

Technologies Used

• Python for core application logic
• Boto3 for AWS SDK integration
• Tkinter for GUI development
• AWS Services: EC2, S3, Route53, IAM
• argparse for CLI argument parsing

Technical Achievements

• Developed dual interface (CLI and GUI) for different user preferences
• Implemented automated IAM policy application for security compliance
• Created resource tagging system for better organization
• Built error handling and validation for AWS operations
• Designed intuitive GUI with Tkinter for non-technical users

Project Overview

A comprehensive expense management system with a professional RESTful API backend. Features include CRUD operations, monthly reporting, automated testing, and production deployment with health monitoring.

Video Demo

Key Features

• RESTful API: Complete CRUD operations following REST principles
• MongoDB Atlas Integration: Cloud database with Mongoose ODM and optimized schemas
• Computed Pattern: Cached monthly reports for improved performance
• Professional Logging: Pino logger for structured logging
• Comprehensive Testing: Jest test suite with Supertest for API testing
• Production Deployment: Hosted on Render with health check endpoints
• API Documentation: Complete API documentation with examples
• Error Handling: Robust error handling with meaningful error messages

Technologies Used

• Node.js & Express.js for API development
• MongoDB Atlas for cloud database
• Mongoose for data modeling
• Jest & Supertest for testing
• Pino for logging
• Render for deployment

Technical Achievements

• Implemented computed pattern for optimized monthly report generation
• Created comprehensive test coverage with Jest
• Designed RESTful API following industry best practices
• Deployed to production with continuous health monitoring
• Structured logging for debugging and monitoring