The system-design-primer is the go-to starting point for systems knowledge: learn how to design large-scale systems, prep for the system design interview, and review with built-in Anki flashcards. One of the most-starred repositories on GitHub (364k stars, 58k forks).
What’s inside:
- Step-by-step system design intro — client-server, DNS, CDN, load balancers, caching, databases, queues, and the rest of the stack in order.
- Scalable design patterns — sharding, replication, consistency models, availability tradeoffs, each with worked examples.
- Interview prep material — real system design questions, solutions, and tradeoff walkthroughs.
- Anki flashcards — spaced-repetition decks so the concepts actually stick.
- Diagrams throughout — the whole thing is annotated diagrams plus text, which makes each pattern click fast.
Why it’s a favorite: it’s the rare resource that turns interview prep into real systems knowledge — the tradeoff framing (CAP, consistency vs availability, caching strategies) transfers directly to day-to-day architecture work.