System design is the blind leading the blind. An interviewer whose never written and wouldn't recognize a "scalable architecture" before asks a candidate to design one in front of them. The candidate pretends to write a scalable architecture, and the interviewer pretends to know when it's correct.
System interview skills are best taught with a class on how to use "Microsoft Visio".
System interview skills are best taught with a class on how to use "Microsoft Visio".