E-commerce Platform - Real-world AWS Architecture

🛒 Business Requirements

Functional Requirements

  • Product catalog: 100,000+ products với search/filter
  • User management: Registration, authentication, profiles
  • Shopping cart: Session management, persistent carts
  • Order processing: Payment, inventory, fulfillment
  • Admin portal: Inventory management, analytics
  • Mobile app: iOS/Android native applications

Non-functional Requirements

  • Availability: 99.9% uptime (8.76 hours downtime/year)
  • Performance: Page load < 2 seconds globally
  • Scalability: Handle Black Friday traffic (10x normal)
  • Security: PCI DSS compliance for payments
  • Disaster Recovery: RTO < 4 hours, RPO < 1 hour

🏗️ High-Level Architecture

                    Internet
                       |
                [CloudFront CDN]
                       |
            [Route 53 DNS + Health Checks]
                       |
                [Application Load Balancer]
                       |
        ┌──────────────┼──────────────┐
        |              |              |
    [Web Tier]    [API Gateway]   [Admin Portal]
        |              |              |
    ┌───┴───┐     ┌────┴────┐    ┌────┴────┐
    | React |     | Lambda  |    | Angular |
    | App   |     | Functions|    | Admin   |
    └───────┘     └─────────┘    └─────────┘
                       |
            [Microservices on ECS/Fargate]
                       |
    ┌─────────┬────────┼────────┬─────────┐
    |         |        |        |         |
[User Svc] [Product] [Order] [Payment] [Inventory]
    |         |        |        |         |
    └─────────┴────────┼────────┴─────────┘
                       |
    ┌─────────────────────────────────────┐
    |              Data Layer              |
    | RDS(Users) DynamoDB(Catalog,Orders) |
    | ElastiCache(Sessions) S3(Images)    |
    └─────────────────────────────────────┘

🌐 Frontend & CDN Layer

CloudFront Configuration

CloudFront Distribution:
  Origins:
    - S3 bucket: Static assets (images, CSS, JS)
    - ALB: Dynamic content

  Behaviors:
    /api/*: Forward to ALB with headers
    /static/*: Cache S3 content (1 year TTL)
    /images/*: Cache S3 content với image optimization

  Security:
    - Origin Access Identity (OAI) for S3
    - WAF integration for DDoS protection
    - SSL/TLS termination

Route 53 Setup

DNS Configuration:
  Primary: ecommerce.com → CloudFront
  API: api.ecommerce.com → ALB
  Admin: admin.ecommerce.com → ALB

Health Checks:
  - Primary region ALB health
  - Database connectivity check
  - Critical service endpoints

Failover:
  - Active-passive setup
  - Automatic failover to DR region

⚖️ Load Balancer & Web Tier

Application Load Balancer

ALB Configuration:
  Listeners:
    - Port 443 (HTTPS): SSL termination
    - Port 80 (HTTP): Redirect to HTTPS

  Target Groups:
    - Web servers: ECS tasks running React app
    - API Gateway: API endpoints
    - Admin portal: ECS tasks running Angular

  Health Checks:
    - Health check path: /health
    - Interval: 30 seconds
    - Timeout: 5 seconds

Web Application Hosting

ECS Service (React App):
  Task Definition:
    - Image: nginx:alpine với React build
    - CPU: 256, Memory: 512MB
    - Environment variables từ Parameter Store

  Service:
    - Desired count: 2 (minimum for HA)
    - Auto Scaling: Based on CPU và ALB requests
    - Rolling deployments: Zero-downtime updates

🔧 Microservices Architecture

API Gateway Configuration

API Gateway:
  Stage: prod
  Throttling: 5000 requests/second
  Caching: TTL varies by endpoint

  Authentication:
    - Cognito User Pools for customers
    - IAM roles for admin functions

  Resources:
    /users: User management service
    /products: Product catalog service  
    /orders: Order processing service
    /payments: Payment processing service

User Management Service

User Service (ECS):
  Container:
    - Image: Spring Boot application
    - CPU: 512, Memory: 1GB
    - Auto Scaling: 2-10 tasks

  Database: RDS PostgreSQL
  Cache: ElastiCache Redis

  Features:
    - User registration/login
    - Profile management
    - Cognito integration
    - JWT token validation

Product Catalog Service

Product Service (Lambda):
  Runtime: Node.js 18
  Memory: 1GB
  Timeout: 30 seconds

  Database: DynamoDB
    - Partition key: CategoryID
    - Sort key: ProductID
    - GSI: Brand, Price range

  Search: Amazon OpenSearch
  Images: S3 với CloudFront

Order Processing Service

Order Service (ECS):
  Container:
    - Image: Python Flask application
    - CPU: 1024, Memory: 2GB
    - Auto Scaling: 2-20 tasks

  Database: DynamoDB
    - Partition key: CustomerID
    - Sort key: OrderDate
    - GSI: OrderStatus for fulfillment

  Queue: SQS for order processing
  Dead Letter Queue: Failed order handling

💳 Payment Processing

Payment Service Architecture

Payment Service:
  Platform: Lambda (isolated for security)
  VPC: Private subnets only

  Integration:
    - Stripe API for payment processing
    - AWS Payment Cryptography for PCI compliance
    - Secrets Manager for API keys

  Data Storage:
    - RDS encrypted for transaction logs
    - No card data stored (tokenization)

PCI DSS Compliance

Security Measures:
  Network:
    - Private VPC với strict NACLs
    - Security Groups allowing minimal access
    - VPC endpoints for AWS services

  Data Protection:
    - Encryption at rest (KMS)
    - Encryption in transit (TLS 1.2+)
    - Tokenization of sensitive data

  Access Control:
    - IAM roles với least privilege
    - MFA for administrative access
    - CloudTrail logging

📊 Data Layer Architecture

Database Strategy

RDS PostgreSQL (User Data):
  Instance: db.r5.xlarge
  Multi-AZ: Yes
  Read Replicas: 2 (for reporting)
  Backup: 7 days retention
  Encryption: KMS encrypted

DynamoDB (Product & Orders):
  Capacity: On-demand mode
  Global Tables: Multi-region replication
  Backup: Point-in-time recovery
  Encryption: Customer managed KMS keys

ElastiCache Redis (Sessions):
  Node: cache.r6g.large
  Cluster: 3 nodes với failover
  Backup: Daily snapshots
  Use case: Session storage, caching

Search & Analytics

Amazon OpenSearch:
  Domain: Product search và analytics
  Instance: r6g.large.search
  Storage: 100GB GP3

  Indexes:
    - Products: Full-text search
    - Orders: Analytics queries
    - Users: Customer segmentation

Kinesis Data Analytics:
  Real-time analytics on order stream
  Fraud detection algorithms
  Customer behavior analysis

🔄 Event-Driven Processing

Order Processing Flow

Order Creation:
  1. API Gateway → Order Service (Lambda)
  2. Validate order → DynamoDB
  3. Send to SQS queue
  4. Trigger processing functions:
     - Inventory check
     - Payment processing  
     - Email notification
     - Shipping label generation

Inventory Management

Inventory Service:
  Platform: ECS với SQS integration

  Real-time Updates:
    - DynamoDB Streams → Lambda
    - Update search index
    - Trigger low stock alerts
    - Update recommendation engine

📱 Mobile Backend

API Design

Mobile API:
  Authentication: Cognito User Pools
  API Gateway: Separate stage for mobile

  Optimizations:
    - GraphQL for flexible queries
    - Caching strategies
    - Offline support considerations
    - Push notifications via SNS

Push Notifications

SNS Configuration:
  Platforms: iOS (APNS), Android (FCM)

  Triggers:
    - Order status updates
    - Promotional campaigns
    - Abandoned cart reminders
    - Inventory restocks

📈 Monitoring & Observability

CloudWatch Dashboard

Business Metrics:
  - Orders per minute
  - Revenue tracking
  - Conversion rates
  - Cart abandonment rate

Technical Metrics:
  - API response times
  - Error rates by service
  - Database performance
  - Cache hit rates

Alerting Strategy

Critical Alerts:
  - Payment processing failures
  - Database connectivity issues
  - High error rates (>5%)
  - API latency >2 seconds

Business Alerts:
  - Sudden drop in orders
  - High cart abandonment
  - Inventory low stock
  - Fraud detection triggers

🚀 Scaling Strategies

Auto Scaling Configuration

ECS Auto Scaling:
  Target Tracking:
    - CPU utilization: 70%
    - Memory utilization: 80%
    - ALB requests per target: 1000

  Scheduled Scaling:
    - Scale up before known traffic peaks
    - Black Friday preparation
    - Marketing campaign periods

Lambda Concurrency:
  Reserved: 100 for payment processing
  Provisioned: For low-latency endpoints

Database Scaling

Read Scaling:
  RDS Read Replicas: For reporting queries
  DynamoDB: Auto-scaling enabled
  ElastiCache: Cluster mode scaling

Write Scaling:
  DynamoDB: On-demand mode
  RDS: Vertical scaling during maintenance
  Queue-based processing: SQS for async writes

💰 Cost Optimization

Cost Management

Reserved Instances:
  - RDS: 1-year term for predictable workload
  - ElastiCache: Reserved nodes
  - EC2 (ECS): Mixed instance types

Savings Plans:
  - Compute Savings Plans for Lambda/Fargate
  - 1-year commitment for stable services

Cost Monitoring:
  - CloudWatch billing alerts
  - Cost Explorer analysis
  - Service-level cost allocation tags

🔒 Security Implementation

Defense in Depth

Network Security:
  - VPC với private subnets
  - Security Groups restrictive rules
  - NACLs for additional protection
  - WAF for application-level protection

Application Security:
  - JWT token validation
  - Input validation và sanitization
  - OWASP compliance
  - Regular security scanning

Data Security:
  - Encryption at rest và in transit
  - Secrets Manager for credentials
  - IAM roles với least privilege
  - Regular access reviews

🧪 Testing Strategy

Testing Pyramid

Unit Tests:
  - Service-level testing
  - 80%+ code coverage
  - Automated in CI/CD pipeline

Integration Tests:
  - API contract testing
  - Database integration tests
  - Third-party service mocks

Load Testing:
  - JMeter scripts for peak loads
  - Chaos engineering with AWS Fault Injection
  - Regular performance benchmarks

📈 Performance Optimization

Caching Strategy

Multi-layer Caching:
  Level 1: Browser cache (static assets)
  Level 2: CloudFront (global CDN)
  Level 3: API Gateway cache
  Level 4: ElastiCache (application data)
  Level 5: Database query cache

Database Optimization

Query Optimization:
  - DynamoDB access patterns design
  - RDS index optimization
  - Connection pooling
  - Read replica distribution

Performance Monitoring:
  - RDS Performance Insights
  - DynamoDB CloudWatch metrics
  - Application Performance Monitoring (APM)

📖 Lessons Learned

Architectural Decisions

  1. Microservices: Provides scalability but adds complexity
  2. Serverless vs Containers: Lambda for variable loads, ECS for consistent workloads
  3. Database choice: DynamoDB for scale, RDS for complex queries
  4. Event-driven: Improves resilience but requires careful design

Cost Considerations

  • Data transfer costs: Use CloudFront và VPC endpoints
  • Database costs: Right-size instances và use read replicas wisely
  • Compute costs: Mix of Reserved Instances và Spot for batch jobs
  • Storage costs: Use S3 lifecycle policies

Kiến trúc này cung cấp foundation cho scalable, secure, và cost-effective e-commerce platform trên AWS, demonstrating real-world application của AWS services trong business context.