Lacks structural consistency

I’m noticing that a lot of system design problems in general lacks consistency. The general guideline is:

  1. ask clarification questions / gather requirements
  2. back-of-the-envelope estimation
  3. API/entity design
  4. High-level design
  5. Deep dive into core components of the system
  6. Identify bottlenecks and system constraints

A lot of examples are missing 3) which is crucial to system design interview. Please be consistent with your solutions.