A Practical Guide to System Design Interviews

What Interviewers Actually Look For

Clear communication and trade-off reasoning matter more than reciting a textbook architecture.

A Repeatable Framework

Clarify requirements, estimate scale, sketch a high-level design, then go deep on the one or two components that matter most.

Common Pitfalls

Jumping straight to a solution without clarifying requirements is the single most common mistake candidates make.

Practice Plan

Work through a handful of classic problems — a URL shortener, a chat system, a news feed — until the framework becomes second nature.