System Design
From CAP theorem to designing a Twitter-scale feed. Each chapter explains the why, not just the what.
System Design Fundamentals
Latency, throughput, availability, durability, and the CAP theorem — the vocabulary you'll use forever.
Scaling: Vertical, Horizontal, and Sharding
How systems grow from one box to thousands, and the strategies for splitting state across them.
Caching: Where, What, When
The single highest-leverage tool in performance work — and the easiest place to introduce subtle bugs.
Databases: SQL vs NoSQL, Indexes, Replication
How to pick a database, what an index actually is, and why replication is non-negotiable.
Queues, Streams & Async Workflows
How decoupled services talk to each other without falling over — message queues, event streams, and pub/sub.
Case Study: Design a Twitter-like Feed
End-to-end walkthrough of the most-asked system design interview question.
Case Study: URL Shortener
The smallest interesting system design problem — and a great showcase of read-heavy optimization.