LearnHub(Microservices Architecture)

📌 Purpose and Scope

LearnHub is a microservices-based e-learning platform built with .NET 9.0.
It provides a complete ecosystem for course creation, student enrollment, order management, and real-time notifications.

This project demonstrates:

• Distributed system design
• Clean Architecture & Domain-Driven Design (DDD)
• Event-driven communication with RabbitMQ
• API Gateway with YARP
• Polyglot persistence with PostgreSQL, SQL Server, and Redis

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🚀 Platform Overview

LearnHub enables:

• Instructors → Create and manage courses, quizzes, and assessments
• Students → Browse, purchase, and enroll in courses
• System → Manages lifecycle from browsing → enrollment → progress tracking

🔑 Core Business Capabilities

• ✅ Course creation and management
• ✅ Student registration & authentication
• ✅ Course catalog browsing & search
• ✅ Shopping cart & order processing
• ✅ Course enrollment
• ✅ Real-time notifications (SignalR)
• ✅ Quiz and assessment management

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🏗️ System Architecture

LearnHub follows a distributed microservices architecture:

• API Gateway Layer → YARP API Gateway (Port 1000)
• Core Business Services → Independent microservices per domain
• Data Layer → Dedicated data stores (SQL Server, PostgreSQL, Redis)
• Messaging Infrastructure → RabbitMQ for async events

Architecture Diagram

Sequence Flow Example

Data Base Schema

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🧩 Microservice Composition

Service	Container Name	Port	Database	Responsibility
Users.API	usersapi	5000	PostgreSQL (UserDb)	Authentication, user management
Course.API	coursesapi	7000	SQL Server (CourseDb)	Courses, lectures, quizzes
Order.API	orderapi	8000	SQL Server (OrderDb)	Order processing, payments
Cart.API	shoppingcart-api	9000	Redis	Shopping cart management
Enrollment.API	enrollmentapi	5555	PostgreSQL (EnrollDb)	Course enrollments
Notification.API	notificationapi	6000	PostgreSQL (NotifDb)	Real-time notifications

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🛠️ Technology Stack

Core Technologies

• .NET 9.0 – Primary runtime
• ASP.NET Core – Web API framework
• Carter – Minimal API routing
• MediatR – CQRS & request handling
• Entity Framework Core – ORM for SQL Server
• Marten – Event store on PostgreSQL

Infrastructure

• YARP – API Gateway
• RabbitMQ – Message broker
• PostgreSQL – User, Enrollment, Notifications
• SQL Server – Courses, Orders
• Redis – Caching & shopping cart
• Docker & Docker Compose – Containerization

Communication Patterns

• HTTP/REST – Synchronous calls
• SignalR – Real-time updates
• RabbitMQ – Event-driven async messaging
• Swagger/OpenAPI – API documentation

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📦 Development & Deployment

Container Orchestration

• Service Containers → Each microservice isolated
• Database Containers → PostgreSQL, SQL Server, Redis
• Infrastructure → RabbitMQ for async messaging

Networks:

• LearnHubNetwork → Main communication layer
• UserNetwork, CourseNetwork, OrderNetwork → Service isolation
• NotificationNetwork, EnrollmentNetwork → Specialized domains

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📚 Core Business Domains

• User Management → Authentication & profiles
• Educational Content → Courses, lectures, quizzes
• Commerce → Shopping cart, orders, payments
• Communication → Notifications & real-time updates

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▶️ Getting Started

Prerequisites

• Docker & Docker Compose
• .NET 9.0 SDK
• SQL Server & PostgreSQL clients

Run Locally

# Clone repo
git clone https://github.com/ahmed-ateya1/LearnHub
cd learnhub

# Build and start services
docker-compose up --build

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🤝 Contribution

Contributions are welcome!
Please open an issue or submit a PR for improvements.

📜 License

This project is licensed under the MIT License.