System Design Primer

The System Design Primer is an organized collection of resources for learning how to design large-scale systems, and one of the most widely used study guides for the system design interview. It walks through the core building blocks (scalability, load balancing, caching, databases, and more) with diagrams, discussion of trade-offs, and worked interview questions with solutions. Anki flashcard decks are included for retention, and community translations cover many languages. Useful both as interview prep and as a practical map of distributed-systems fundamentals.