A robust, scalable real-time chat application built with a modern microservices architecture. This project demonstrates advanced backend skills, including distributed systems, polyglot persistence, and event-driven communication.

This application is designed to handle real-time messaging with a focus on scalability and decoupling. It uses a monorepo structure managed by pnpm workspaces to organize distinct services.

• Microservices Architecture: Functionally decomposed services for Auth and User management.
• Event-Driven Communication: Asynchronous messaging between services using RabbitMQ to ensure loose coupling and reliability.
• Polyglot Persistence: Usage of the right database for the right job — MySQL for authentication/transactional data and PostgreSQL for user profiles.
• Type Safety: End-to-end type safety with TypeScript shared across services.
• Containerization: Fully containerized environment using Docker and Docker Compose for consistent development and deployment.

• Language: TypeScript (Node.js)
• Framework: Express.js
• Package Manager: pnpm (Monorepo Workspaces)

• Auth Service: Handles registration, login, and JWT issuance.
  • Database: MySQL
  • ORM: Sequelize
  • Validation: Zod
  • Security: Bcrypt, Helmet
• User Service: Manages user profiles and discovery.
  • Database: PostgreSQL
  • ORM: Sequelize

• Message Broker: RabbitMQ (amqplib)
• Containerization: Docker, Docker Compose

├── packages
│   └── common          # Shared libraries, types, and utilities
├── services
│   ├── auth-service    # Authentication & Authorization (MySQL)
│   ├── user-service    # User Profile Management (PostgreSQL)
│   └── gateway-service # API Gateway (planned/in-progress)
├── docker-compose.yaml # Orchestration for DBs and Broker
├── package.json        # Root workspace config
└── pnpm-workspace.yaml # Workspace definitions

• Node.js (v18+)
• pnpm (npm install -g pnpm)
• Docker & Docker Compose

1. Clone the repository

   git clone <repository-url>
   cd chat-app

2. Install dependencies

   pnpm install

3. Start Infrastructure Spin up the databases (MySQL, Postgres) and RabbitMQ.

   docker-compose up -d

4. Run Services (Development) You can run services individually or all together depending on the script setup.

   # Run all services in dev mode (if script exists)
   pnpm run dev
   
   # OR run specific service
   pnpm --filter @chat-app/auth-service run dev
   pnpm --filter @chat-app/user-service run dev

Each service has its own .env configuration (mapped from docker-compose.yaml or .env files).

Common Variables:

• PORT: Service port
• RABBITMQ_URL: AMQP connection string
• DB_HOST, DB_USER, DB_PASS, DB_NAME: Database credentials

1. Fork the Project
2. Create your Feature Branch (git checkout -b feature/AmazingFeature)
3. Commit your Changes (git commit -m 'Add some AmazingFeature')
4. Push to the Branch (git push origin feature/AmazingFeature)
5. Open a Pull Request