Why Dual Database Architecture?​

LearnFlow uses both PostgreSQL and MongoDB to optimize for different data access patterns:

PostgreSQL (Relational) - Structured Data​

Use Cases:

• User accounts and authentication
• Course metadata
• Enrollments
• Audit logs
• Discussion comments

Rationale:

• ACID Compliance: Critical for financial and user data
• Structured Relationships: Users → Courses → Enrollments
• Query Flexibility: Complex joins for analytics
• Maturity: Battle-tested for production systems

MongoDB (NoSQL) - Flexible Content​

Use Cases:

• Course lessons (varying structures)
• User progress (variable per user)
• Rich content with different schemas

Rationale:

• Flexible Schema: Lessons can have different content types
• Scalability: Handle growing content libraries
• Document Model: Natural fit for lesson-progress relationships
• Rapid Development: Easy schema evolution

Frontend Architecture​

Our frontend is built with:

• React 19: Modern UI component library with hooks
• Vite: Fast build tool and development server
• React Router: Client-side routing
• Tailwind CSS: Utility-first CSS framework
• Framer Motion: Animations and transitions

Key Frontend Patterns​

1. Context API: Used for global state management (Auth, Theme)
2. Protected Routes: Role-based route protection
3. Service Layer: Centralized API calls
4. Component Composition: Reusable, composable components

Backend Architecture​

Our backend is built with:

• FastAPI: Modern Python web framework
• SQLAlchemy: SQL ORM toolkit
• JWT: Token-based authentication
• bcrypt: Password hashing
• slowapi: Rate limiting

Key Backend Patterns​

1. Dependency Injection: FastAPI's Depends for database sessions
2. Pydantic Schemas: Request/response validation
3. Middleware: CORS, rate limiting, error handling
4. Service Layer: Separated business logic

Authentication Flow​

┌──────────┐      ┌──────────┐      ┌──────────┐
│  Client  │      │  Backend │      │ Database │
└──────────┘      └──────────┘      └──────────┘
     │                  │                  │
     │ POST /login      │                  │
     │─────────────────>│                  │
     │                  │ Verify password  │
     │                  │─────────────────>│
     │                  │                  │
     │                  │<─────────────────│
     │                  │                  │
     │                  │ Create JWT token │
     │                  │─────────────────>│
     │                  │                  │
     │<─────────────────│                  │
     │ JWT token        │                  │

Design Decisions​

1. FastAPI over Flask/Django​

Decision: Use FastAPI for the backend.

Rationale:

• Automatic OpenAPI documentation
• Native async support for better performance
• Type validation with Pydantic
• Modern Python features

2. React with Vite​

Decision: Use React 19 with Vite build tool.

Rationale:

• Fast development server
• Optimized production builds
• Large ecosystem
• Modern hooks API

3. JWT over Sessions​

Decision: Stateless JWT authentication.

Rationale:

• Scalable across multiple servers
• No session storage needed
• Mobile-friendly tokens

4. Dual Database​

Decision: PostgreSQL + MongoDB.

Rationale:

• PostgreSQL for ACID-critical data (users, payments)
• MongoDB for flexible content (lessons, progress)

What's Next?​

We're planning to evolve our architecture with:

• Microservices decomposition
• Event-driven architecture
• Advanced caching strategies
• Real-time features with WebSockets

Learn More​

Check out our architecture documentation for more details.

What is LearnFlow?​

LearnFlow is a comprehensive Learning Management System that enables administrators to create and manage courses while allowing learners to browse, enroll, and track their progress through lessons.

Key Features​

For Learners​

• 📚 Browse and search courses by category and level
• 🎯 Track learning progress with visual indicators
• 📖 Interactive lesson viewer (video and text content)
• 🏆 Course leaderboards
• 💬 Course discussions and Q&A
• 💬 Direct messaging with instructors
• 🌙 Dark/Light theme support
• 📱 Fully responsive design

For Administrators​

• 📊 Comprehensive analytics dashboard
• 📝 Course creation and management
• 📖 Lesson management with multiple content types
• 👥 User management with role-based access
• 📋 Audit logs for security and compliance
• 📈 Platform insights and reporting
• 📅 Activity reports and trends

Tech Stack​

LearnFlow is built with modern technologies:

• Frontend: React 19, Vite, Tailwind CSS, Framer Motion
• Backend: FastAPI, SQLAlchemy, JWT Authentication
• Databases: PostgreSQL (relational), MongoDB (NoSQL)
• DevOps: Docker, Docker Compose

Getting Started​

Get started with LearnFlow in minutes:

# Clone the repository
git clone <your-repo-url>
cd learnflow_app

# Start all services with Docker Compose
docker compose up --build

The application will be available at:

• Frontend: http://localhost:3000
• Backend API: http://localhost:8000
• API Documentation: http://localhost:8000/docs

What's Next?​

We're continuously working to improve LearnFlow. Stay tuned for:

• Mobile application
• Advanced analytics
• Integration with third-party services
• Enhanced collaboration features

Learn More​

Check out our documentation to learn more about LearnFlow's features and architecture.