Architecture Overview¶

This document provides a high-level overview of the NSGG Backend architecture.

System Architecture¶

┌─────────────────┐     ┌─────────────────┐     ┌─────────────────┐
│   Client Apps   │     │   API Gateway   │     │ Load Balancer   │
│  Web/Mobile/API │────▶│     (Nginx)     │────▶│    (HAProxy)    │
└─────────────────┘     └─────────────────┘     └─────────────────┘
                                                         │
                                                         ▼
┌─────────────────┐     ┌─────────────────┐     ┌─────────────────┐
│    Monitoring   │     │   Application    │     │    Database     │
│ Prometheus/Graf │◀────│  Django/DRF/    │────▶│   PostgreSQL    │
└─────────────────┘     │   Gunicorn      │     └─────────────────┘
                        └─────────────────┘
                                │
                                ▼
                        ┌─────────────────┐
                        │     Cache       │
                        │     Redis       │
                        └─────────────────┘

Core Components¶

1. API Gateway (Nginx)¶

• SSL termination
• Request routing
• Static file serving
• Rate limiting
• Load balancing

2. Application Servers¶

• Django/DRF application
• Business logic
• API endpoints
• Authentication/Authorization
• Data validation

3. Database (PostgreSQL)¶

• Persistent data storage
• Complex queries
• Data integrity
• Backups and replication

4. Cache Layer (Redis)¶

• Session storage
• API response caching
• Rate limiting
• Task queue backend

Application Structure¶

nsgg_backend/
├── config/                 # Project configuration
├── products/              # Product management
├── users/                 # User management
├── orders/               # Order processing
├── common/               # Shared utilities
└── tests/                # Global test utilities

Key Features¶

1. Authentication and Authorization¶

• JWT-based authentication
• Role-based access control
• Token refresh mechanism
• Session management

2. Product Management¶

• Product catalog
• Category hierarchy
• Inventory tracking
• Price management

3. Order Processing¶

• Shopping cart
• Order creation
• Payment processing
• Order fulfillment

4. User Management¶

• User registration
• Profile management
• Address management
• Permission system

Data Flow¶

1. Request Flow¶

Client Request
    ↓
Nginx (SSL/routing)
    ↓
Load Balancer
    ↓
Django Application
    ↓
Cache/Database
    ↓
Response

2. Order Flow¶

Cart Creation
    ↓
Add Products
    ↓
Checkout Process
    ↓
Payment Processing
    ↓
Order Confirmation
    ↓
Fulfillment

Security Measures¶

1. Authentication¶

• JWT tokens
• Secure password storage
• 2FA support
• Session management

2. Data Protection¶

• SSL/TLS encryption
• Data encryption at rest
• Secure headers
• CSRF protection

3. Access Control¶

• Role-based permissions
• API rate limiting
• IP whitelisting
• Audit logging

Caching Strategy¶

1. Multi-level Caching¶

Browser Cache
    ↓
CDN Cache
    ↓
Application Cache
    ↓
Database Cache

2. Cache Keys¶

• Product listings
• User sessions
• API responses
• Static assets

Performance Optimizations¶

1. Database¶

• Indexing strategy
• Query optimization
• Connection pooling
• Regular maintenance

2. Application¶

• Response caching
• Async processing
• Batch operations
• Resource compression

Monitoring and Logging¶

1. Metrics¶

• Request latency
• Error rates
• Resource usage
• Business metrics

2. Logging¶

• Application logs
• Access logs
• Error tracking
• Audit trails

Scalability¶

1. Horizontal Scaling¶

• Multiple app servers
• Database replication
• Cache clustering
• Load balancing

2. Vertical Scaling¶

• Resource allocation
• Query optimization
• Caching strategy
• Background tasks

Dependencies¶

1. Core Dependencies¶

• Django
• Django REST Framework
• PostgreSQL
• Redis

2. Additional Services¶

• Stripe (payments)
• AWS S3 (storage)
• SendGrid (email)
• Sentry (error tracking)

Development Workflow¶

1. Local Development¶

• Docker environment
• Development tools
• Testing framework
• Documentation

2. Deployment¶

• CI/CD pipeline
• Environment config
• Monitoring setup
• Backup strategy

Future Considerations¶

1. Planned Features¶

• Real-time updates
• Advanced search
• Analytics dashboard
• Mobile API

2. Scalability Plans¶

• Microservices
• Event streaming
• GraphQL API
• Global CDN