NestJS Modular Monolith CQRS Event Sourcing Architecture Template 🚀

Welcome to the NestJS Modular Monolith CQRS Event Sourcing Architecture Template. This repository provides a scalable NestJS project template that supports modular monolith architecture, CQRS (Command Query Responsibility Segregation), and Event Sourcing. Built with Domain-Driven Design (DDD) and Onion Architecture principles, this template is ideal for developing proof-of-concept (PoC) projects and production-ready backend systems.

Table of Contents

• Features
• Technologies
• Getting Started
• Project Structure
• Usage
• Contributing
• License
• Releases

Features

• Modular Monolith Architecture: Organize your codebase into distinct modules for better maintainability.
• CQRS Support: Separate read and write operations for improved performance and scalability.
• Event Sourcing: Store state changes as a sequence of events, allowing for better auditing and recovery.
• Domain-Driven Design: Focus on the core domain and its logic, improving communication and collaboration among team members.
• Onion Architecture: Promote a clean separation of concerns and dependency management.
• Flexible Database Support: Choose from MongoDB, PostgreSQL, SQLite, or other databases as per your requirements.
• Docker and Docker Compose: Easily deploy your application using containerization.

Technologies

This template incorporates a variety of technologies to enhance functionality and performance:

• NestJS: A progressive Node.js framework for building efficient, reliable, and scalable server-side applications.
• CQRS: Command Query Responsibility Segregation pattern for separating read and write operations.
• Event Sourcing: Storing state changes as a sequence of events.
• MongoDB: A NoSQL database for high-performance data storage.
• Kafka: A distributed streaming platform for building real-time data pipelines.
• EventStoreDB: A database specifically designed for event sourcing.
• PostgreSQL: An open-source relational database.
• SQLite: A lightweight database engine.
• TypeScript: A superset of JavaScript that compiles to plain JavaScript.

Getting Started

To get started with this template, clone the repository and install the dependencies. Follow these steps:

1. Clone the repository:

   git clone https://github.com/aligcgl/nestJS-modular-monolith-cqrs-event-sourcing-architecture-template.git

2. Navigate into the project directory:

   cd nestJS-modular-monolith-cqrs-event-sourcing-architecture-template

3. Install the dependencies:

   npm install

4. Set up your environment variables. Create a .env file based on the provided .env.example file.

5. Start the application:

   npm run start:dev

Your application should now be running on http://localhost:3000.

Project Structure

The project is organized into several key directories:

src/
├── modules/             # Contains feature modules
│   ├── users/           # User module
│   ├── products/        # Product module
│   └── orders/          # Order module
├── shared/              # Shared utilities and constants
├── infrastructure/      # Infrastructure-related code (database, messaging)
└── main.ts              # Entry point of the application

Modules

Each module contains its own controllers, services, and entities. This separation allows for easier testing and maintenance.

Shared

The shared directory includes common utilities, constants, and interfaces that can be used across different modules.

Infrastructure

This directory contains the configuration for databases, messaging systems, and other infrastructure components.

Usage

To utilize this template effectively, consider the following:

1. Define your domain: Identify the core business logic and domain entities that your application will manage.

2. Create modules: Structure your application into modules based on the domain entities. Each module should encapsulate its own logic and dependencies.

3. Implement CQRS: Separate your commands (writes) and queries (reads) to optimize performance and maintainability.

4. Utilize Event Sourcing: Implement event sourcing to track changes in your application state. This allows for better auditing and the ability to replay events if needed.

5. Deploy with Docker: Use Docker and Docker Compose for deployment. Create a docker-compose.yml file to define your services and run them with a single command.

Contributing

Contributions are welcome! If you would like to contribute to this project, please follow these steps:

1. Fork the repository.
2. Create a new branch for your feature or bug fix.
3. Make your changes and commit them.
4. Push your branch to your forked repository.
5. Create a pull request describing your changes.

Please ensure that your code adheres to the project's coding standards and is well-documented.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Releases

For the latest releases, please visit the Releases section. You can download and execute the latest files from there.

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This README provides a comprehensive overview of the NestJS Modular Monolith CQRS Event Sourcing Architecture Template. Use it as a guide to navigate the project and make the most of its features.