Alex Xu

System Design Interview exists because a specific problem does: engineering candidates are asked to design a URL shortener or a news feed on a whiteboard, and almost no course teaches it.

The book works through a set of these, showing the clarifying questions first, then a rough design, then the scaling decisions and the trade-offs each one forces. Load balancers, sharding, caching, consistency choices.

It is a study guide rather than an architecture text, and it is honest about that. Volume two covers the harder problems.