System Architecture Diagram

Overview

This document describes the high-level system architecture of the Learnille platform.

Architecture Principles

Microservices: Modular, independently deployable services
API-First: All interactions through well-defined APIs
Scalability: Horizontal scaling for high availability
Security: Defense in depth with multiple security layers
Observability: Comprehensive logging, monitoring, and tracing

High-Level Architecture

┌─────────────────────────────────────────────────────────────────┐
│                    Client Layer                                 │
│  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────┐ │
│  │   Web Client    │  │   Mobile App    │  │   Admin Panel    │ │
│  │   (React)       │  │   (React Native)│  │   (React)        │ │
│  └─────────────────┘  └─────────────────┘  └─────────────────┘ │
└─────────────────────────────────────────────────────────────────┘
                                   │
                                   ▼
┌─────────────────────────────────────────────────────────────────┐
│                   API Gateway Layer                              │
│  ┌─────────────────┐                                           │
│  │   API Gateway   │  (Rate limiting, Authentication, Routing) │
│  │   (Kong/Nginx)  │                                           │
│  └─────────────────┘                                           │
└─────────────────────────────────────────────────────────────────┘
                                   │
                                   ▼
┌─────────────────────────────────────────────────────────────────┐
│                   Service Layer                                  │
│  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────┐ │
│  │   User Service  │  │ Course Service  │  │Consultation Svc  │ │
│  │   (Node.js)     │  │   (Node.js)     │  │   (Node.js)      │ │
│  └─────────────────┘  └─────────────────┘  └─────────────────┘ │
│  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────┐ │
│  │ Payment Service │  │Notification Svc │  │ Analytics Svc    │ │
│  │   (Python)      │  │   (Node.js)     │  │   (Python)       │ │
│  └─────────────────┘  └─────────────────┘  └─────────────────┘ │
└─────────────────────────────────────────────────────────────────┘
                                   │
                                   ▼
┌─────────────────────────────────────────────────────────────────┐
│                   Data Layer                                     │
│  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────┐ │
│  │  PostgreSQL     │  │    Redis        │  │   Elasticsearch  │ │
│  │  (Primary DB)   │  │  (Cache)        │  │   (Search)       │ │
│  └─────────────────┘  └─────────────────┘  └─────────────────┘ │
│  ┌─────────────────┐  ┌─────────────────┐                      │
│  │   OpenSearch    │  │  Cloudflare R2  │                      │
│  │  (Search/Vector)│  │ (Files/Media)   │                      │
│  └─────────────────┘  └─────────────────┘                      │
└─────────────────────────────────────────────────────────────────┘
                                   │
                                   ▼
┌─────────────────────────────────────────────────────────────────┐
│                   Infrastructure Layer                           │
│  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────┐ │
│  │   Docker / PM2  │  │   Self-Hosted   │  │   Nginx Proxy   │ │
│  │ (Containerization│  │ (Linux VPS/Bare)│  │ (Reverse Proxy) │ │
│  └─────────────────┘  └─────────────────┘  └─────────────────┘ │
│  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────┐ │
│  │  New Relic APM  │  │ New Relic Logs  │  │   Security      │ │
│  │ (Performance)   │  │ (Aggregation)   │  │ (WAF, SSL)      │ │
│  └─────────────────┘  └─────────────────┘  └─────────────────┘ │
└─────────────────────────────────────────────────────────────────┘

Component Descriptions

Client Layer

Web Client: React-based single-page application for learners and instructors
Mobile App: React Native application for iOS and Android
Admin Panel: React-based dashboard for platform administrators

API Gateway Layer

API Gateway: Centralized entry point handling authentication, rate limiting, and request routing
Load Balancer: Distributes traffic across service instances
CDN: Content delivery network for static assets and media

Service Layer

User Service: Manages user accounts, authentication, and profiles
Course Service: Handles course creation, management, and content delivery
Consultation Service: Manages one-on-one and group consultation sessions
Payment Service: Processes payments and manages subscriptions
Notification Service: Handles email, SMS, and in-app notifications
Analytics Service: Tracks user behavior and generates insights

Data Layer

PostgreSQL: Primary relational database for structured data
Redis: In-memory cache for session data and frequently accessed information
Elasticsearch: Search engine for course content and user data
MongoDB: Document database for flexible data structures
S3 Storage: Object storage for files, images, and videos

Infrastructure Layer

Docker / PM2: Containerization and process management platform
Self-Hosted VPS: High-performance Linux instances (Hetzner / DigitalOcean / Bare Metal)
Nginx Proxy: Reverse proxy, SSL termination, and rate-limiting ingress
Cloudflare R2: High-performance S3 API object storage with zero egress fees
New Relic: Centralized APM, transaction tracing, and structured log management
Sentry: Real-time exception tracking and error reporting

Data Flow

User Request: Client sends request to API Gateway
Authentication: Gateway validates JWT token and user permissions
Routing: Request routed to appropriate microservice
Business Logic: Service processes request, interacts with databases
Response: Service returns data through gateway to client
Caching: Frequently accessed data cached in Redis
Logging: All requests logged for monitoring and debugging

Security Architecture

Authentication: JWT tokens with refresh mechanism
Authorization: Role-based access control (RBAC)
Encryption: TLS 1.3 for data in transit, AES-256 for data at rest
API Security: Rate limiting, input validation, SQL injection prevention
Network Security: VPC isolation, security groups, WAF

Scalability Considerations

Horizontal Scaling: Services can be scaled independently
Database Sharding: Data partitioned across multiple database instances
CDN Integration: Static content served from edge locations
Auto-scaling: Services scale based on CPU/memory usage
Read Replicas: Database read operations distributed across replicas

Deployment Architecture

CI/CD Pipeline: Automated testing and deployment
Blue-Green Deployment: Zero-downtime deployments
Feature Flags: Gradual feature rollout and rollback
Environment Isolation: Separate environments for dev/staging/prod

Monitoring and Observability

Metrics: Application performance, error rates, user activity
Logging: Structured logs with correlation IDs
Tracing: Distributed tracing for request flow
Alerting: Automated alerts for system issues
Dashboards: Real-time monitoring dashboards

Technology Stack

Frontend

React 18
TypeScript
Redux Toolkit
React Router
Axios

Backend

Node.js (Express/NestJS)
Python (FastAPI)
GraphQL/REST APIs
JWT Authentication

Database

PostgreSQL 15
Redis 7
Elasticsearch 8
Cloudflare R2 (Object Storage)

Infrastructure

Self-Hosted Linux (Hetzner / DigitalOcean / Bare Metal)
Docker & Docker Compose
PM2 Process Manager
Nginx Reverse Proxy

DevOps & Observability

GitHub Actions CI/CD
New Relic APM & Log Management
Sentry Exception Tracking

Future Considerations

Micro-frontend Architecture: Independent frontend applications
Event-Driven Architecture: Asynchronous communication between services
Multi-Cloud Deployment: Hybrid cloud strategy
AI/ML Integration: Machine learning for personalized learning
Blockchain: Credential verification and NFT certificates