kamarbandi/shop_website

Shop Website System Design

This document outlines the system design for a shop website, covering the architecture, components, and workflows necessary to create a scalable, secure, and user-friendly platform.

1. Requirements

Functional Requirements

• User registration and authentication
• Product catalog with categories and search functionality
• Product details view (description, photos, reviews)
• Shopping cart and checkout process
• Payment processing
• Order management and tracking
• User reviews and ratings
• Admin interface for product and order management
• Support for promotional codes and discounts

Non-Functional Requirements

• Scalability to handle high traffic volumes
• High availability and fault tolerance
• Low latency for search and checkout operations
• Security for user data and payment transactions

2. High-Level Architecture

Frontend (Client Layer)

• Web application (React, Angular, or Vue.js)
• Mobile application (iOS and Android using React Native or Flutter)

Backend (Service Layer)

• API Gateway
• Microservices

Database Layer

• SQL Database for transactional data (PostgreSQL, MySQL)
• NoSQL Database for high read throughput (MongoDB, Cassandra)
• Search engine (Elasticsearch)

Infrastructure

• Cloud provider (AWS, Google Cloud, Azure)
• Container orchestration (Kubernetes, Docker)

Third-party Services

• Payment gateway (Stripe, PayPal)
• Email/SMS service (SendGrid, Twilio)

3. Component Design

API Gateway

• Acts as the entry point for all client requests.
• Handles request routing, authentication, rate limiting, and logging.

Microservices

Each service is independently deployable and focused on a specific domain.

• User Service: Handles user registration, authentication, and profile management.
• Product Service: Manages product information, inventory, and pricing.
• Cart Service: Manages the shopping cart for users.
• Order Service: Manages order creation, updates, and tracking.
• Payment Service: Processes payments and handles transaction records.
• Review Service: Manages user reviews and ratings.
• Search Service: Handles search queries and filtering using Elasticsearch.

Database Layer

• SQL Database: Stores structured data such as user information, product details, orders, and transactions.
• NoSQL Database: Stores unstructured data such as reviews, product descriptions, and images.
• Elasticsearch: Provides fast search capabilities with filtering and full-text search.

Horizontal and Vertical Scaling

• Horizontal Scaling:

  • SQL Database: Implement read replicas and sharding. Distribute the load by directing read operations to read replicas while the master handles write operations.
  • NoSQL Database: Use sharding to distribute data across multiple servers, ensuring even distribution of load and data.

• Vertical Scaling:

  • SQL Database: Increase the resources (CPU, RAM, storage) of the database server to handle increased load.
  • NoSQL Database: Similarly, increase resources to accommodate higher loads, focusing on memory and storage.

Infrastructure

• Load Balancer: Distributes incoming requests across multiple servers to ensure high availability.
• Caching: Uses Redis or Memcached to cache frequently accessed data and reduce database load.
• CDN: Delivers static content (images, CSS, JS) quickly to users worldwide.

4. Workflow

User Registration and Authentication

1. User submits registration details via the frontend.
2. API Gateway forwards the request to the User Service.
3. User Service validates and stores user details in the SQL Database.
4. Confirmation email is sent via a third-party email service.

Product Search and Browsing

1. User enters search criteria (keywords, categories, filters) on the frontend.
2. API Gateway forwards the search query to the Search Service.
3. Search Service queries Elasticsearch for matching products.
4. Results are aggregated and returned to the frontend.

Shopping Cart and Checkout

1. User adds products to the shopping cart.
2. API Gateway forwards the request to the Cart Service.
3. Cart Service updates the cart in the NoSQL Database.
4. User proceeds to checkout and provides payment details.
5. API Gateway forwards the request to the Order Service.
6. Order Service verifies product availability and creates an order in the SQL Database.
7. Order Service requests payment processing via the Payment Service.
8. Payment Service processes the payment and confirms the transaction.
9. Order Service finalizes the order and updates the database.
10. Confirmation is sent to the user via email.

User Reviews

1. User submits a review for a product.
2. API Gateway forwards the review to the Review Service.
3. Review Service validates and stores the review in the NoSQL Database.
4. Review is indexed in Elasticsearch for fast retrieval.

5. Security and Compliance

• Data Encryption: Encrypt sensitive data at rest and in transit using TLS/SSL.
• Authentication and Authorization: Use OAuth2.0 and JWT tokens for secure authentication.
• PCI Compliance: Ensure payment processes comply with PCI-DSS standards.
• Monitoring and Logging: Implement centralized logging and monitoring using tools like ELK Stack, Prometheus, and Grafana.

6. Scalability and Fault Tolerance

• Auto-scaling: Use cloud auto-scaling features to handle traffic spikes.
• Database Replication: Implement master-slave replication for high availability.
• Backup and Recovery: Regularly back up databases and have a disaster recovery plan in place.
• Circuit Breaker Pattern: Prevent cascading failures by isolating failures in services.