Fullstack Development

Backend Architecture

Content

• What is backend architecture?
• Backend architecture components
• Backend practices

What is backend architecture?

• The conceptual design and structure of server-side compoments
  • Business logic
  • Data layers
  • Security layers
  • 3rd-party integrations
• Involving deciding on and documentating a blueprint for the system

Backend architecture components

• Servers
• Databases
• APIs
• Caching solutions
• Asynchronous messaging
• Authentication and authorization
• Other components

Example: Netflix backend overview

Servers

• Compute services
  • Bare metal, Virtual machine, Container, Serverless
• Provides resources, data, and services to clients
• Running server-side code
  • business logic, process requests, manage data storage and retrieval

Databases

• Manages, retrieves, and stores data
  • SQL databases organizes data via tables with predefined schema
  • NoSQL databases provides more flexible schema
• Typically implemented via DBMS
  • MySQL, PostgreSQL, MongoDB, Elasticsearch, ...

see more detail in the database design concepts. <HTML | PDF>

APIs

• Application Programming Interfaces
• Provides communication and data exchange between components
• Defines rules, protocols, URIs, URLs and data formats for request/response

Caching Solutions

• Temporarily stores data in fast-access storage layer
• Improveing performance by reducing the need for repeated queiries or API calls
• Implementation options:
  • Web browser's localStorage, Application code (variables)
  • CDNs (Cloudflare Cache, Amazon Cloudfront)
  • In-memory caches (Redis)

Caching Solutions - Redis

Asynchronous messaging

• Enables decoupled, asynchronous communication between sender and receiver
• Messages (requests/responses) are safely stored in a broker
• No waiting for response (better performance, scalability, and reliability)
• Typically used in serverless or microservices architectures
• Messaging pattern : publish-subscribe, FIFO message queues, event streams
• Message broker : BullMQ + Redis, Kafka, RabbitMQ

Asynchronous messaging (2)

Authentication and Authorization

• Ensure that only authenticated client/user can access the system
• Client/user has the necessary permissions to access resources or perform actions
• Authentication methods
  • Password-based, MFA, OAuth
• Authorization policies
  • Role-based access control (RBAC), policy-based access control, ...

Other components

• Object Storage service
  • Amazon S3, Azure Blob Storage, Google Cloud Storage
  • Minio, Garage
• Network services
  • Reverse Proxy: Nginx, Traefik
  • Load balancers, Firewall/Security group
• 3rd-party integrations
  • Payment service: 2C2P, Omise, Stripe, Bank APIs
  • Streaming service

Other components (2)

• Logging and monitoring
  • Application logs, Clickstream, Network logs
• CI/CD pipelines
  • Jenkins
  • GitHub Action, GitLab CI/CD
  • Azure Pipelines, AWS CodePipeline
  • Argo CD (for Kubernetes)
• Infrastructure as code (IaC)
  • Terraform, Ansible

Backend practices

• The scope and nature of backend systems vary across different use cases
  • Types of applications, size, development team, time and budget
• Challenges
  • Ensuring scalability and reliability
  • Effective communication
  • Data managment

Backend practices (2)

• A number of distributed system design patterns have emerged to address common issues
• Utilize a CI/CD pipeline
  • Based on reliable testing and test automation
  • Keep test scripts up to date (update test script along with app code)
  • Regularly maintain test suites (keep test suites lightweight)
  • Choose a suitable testing environment (isolated and representative of prod environment)

Backend practices (3)

• Design for modularity
  • A system should be composed of loosely coupled modules (better scalability)
  • Each module is its own independent unit with minimal dependencies
  • Utilize an API gateway (a single entry point for an app)
    • Receives all client requests
    • Routes them to the correct backend component or service
    • Allows updating and adding new components without affecting the client interface

Example

An example of a system architecture diagram for a microserivces

Reference

• Backend Architecture: Tutorial & Best Practices
• How to Choose a Message Queue?
• Netflix System Design - Backend Architecture 2021