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Master system design through visual learning

Whether you’re preparing for a System Design Interview or you simply want to understand how systems work beneath the surface, System Design 101 will help you achieve that goal. We explain complex systems using visuals and simple terms, making even the most intricate concepts accessible.
This comprehensive resource covers everything from fundamental concepts like APIs and databases to advanced topics like distributed systems and cloud architecture.

What you’ll learn

System Design 101 covers the essential knowledge areas that every software engineer needs to build scalable, reliable systems:

API & web development

Master REST, GraphQL, gRPC, and modern API design patterns. Learn how browsers render pages, HTTP protocols evolve, and load balancers distribute traffic.

Database & storage

Understand SQL vs NoSQL, sharding strategies, replication patterns, and how to choose the right database. Explore Kafka, Redis, and message queue architectures.

Cloud & distributed systems

Learn AWS services, CAP theorem, consistency patterns, and how to design fault-tolerant systems. Master scalability strategies and distributed system patterns.

Caching & performance

Discover Redis architecture, CDN implementation, cache eviction policies, and performance optimization techniques that reduce latency at scale.

Security fundamentals

Master OAuth 2.0, JWT authentication, encryption methods, and how to design secure systems. Learn about HTTPS, SSL handshakes, and password management.

Real-world case studies

Explore how Netflix, Twitter, Uber, Discord, and Airbnb built their systems. Learn from production architectures that serve millions of users.

DevOps & CI/CD

Understand Kubernetes, Docker, deployment strategies, and CI/CD pipelines. Learn how companies ship code to production safely and efficiently.

Software architecture

Study design patterns, microservices architecture, domain-driven design, and the trade-offs in different architectural approaches.

Why System Design 101?

Our approach combines visual diagrams with clear explanations, making complex system design concepts easy to understand and remember.
System Design 101 stands out because:
  • Visual-first approach: Every concept is explained with detailed diagrams that make abstract ideas concrete
  • Real-world examples: Learn from actual production systems at companies like Netflix, Uber, and Discord
  • Interview preparation: Perfect for preparing for system design interviews with comprehensive coverage of common patterns
  • Practical focus: Each topic includes practical use cases and implementation considerations
  • Comprehensive coverage: From fundamentals to advanced topics, covering 15+ major categories
Here are some of the most popular guides that thousands of engineers have found valuable:
  • How does REST API work? - Principles, methods, constraints, and best practices
  • System Design Blueprint - A template to tackle various system design problems
  • How Discord Stores Trillions of Messages - Real-world scalability case study
  • Consistent Hashing Explained - Essential distributed systems concept
  • Top 5 Caching Strategies - Improve performance with the right caching approach
  • OAuth 2.0 Explained - Modern authentication made simple
  • Microservices Best Practices - 9 essential practices for building microservices
  • How to Choose the Right Database - Decision framework for database selection

Get started

How to use this guide

Learn how to navigate the documentation and get the most out of System Design 101

Explore categories

Browse all 15+ categories covering every aspect of system design

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