How to Actually Clarify System Design Requirements in Technical Interviews

A software engineering guide published on DEV Community breaks down how to effectively clarify requirements during system design interviews, going beyond the generic advice of simply 'asking for requirements.' The piece uses a URL shortener as a running example to show how targeted questions — such as whether users are authenticated or what the read-to-write traffic ratio is — directly shape architectural decisions. The author distinguishes between functional requirements, which define what users can do, and non-functional requirements, which set performance, availability, and latency constraints. Rather than treating these as abstract checklists, the guide frames each question as a way to uncover consequences that drive design choices, such as separating analytics from the critical redirect path. The core takeaway is that good requirement clarification follows a chain of reasoning: requirement leads to consequence, which leads to architecture.