The Three Question Families

1. Why Classification Comes First

"Design an AI-powered shopping experience" and "Design a fraud detection system" sound like cousins. They are not. They belong to different families entirely: different architectures, different success metrics, different places where the interview gets won or lost. Answer one with the toolkit built for the other, and you have just made the single most common structural mistake in this interview. It happens fast too, in the first five minutes, before any real design has even begun