System Design Primer

The System Design Primer collects, in one organized place, the material for learning how large-scale systems are put together. Scalability, load balancing, caching and databases each get diagrams and an explicit discussion of trade-offs, alongside worked interview questions with solutions. Anki decks ship with it for retention, and community translations cover a long list of languages. It is best known as one of the most widely used study guides for the system design interview, though nothing about the material changes when you read it as a map of distributed-systems fundamentals instead.