Systems / Application Design Interview Prompt?

This is more of a general question about how one should prepare for Systems / Application design questions specifically for junior-level full stack role. Many of the Systems Design resources seemed to be more geared towards larger companies. My question is how should someone structure their preparation for these types of questions when they are applying to startups.

One example prompt could be: How would you design a form that takes in patient data to be used by other engineers within the team?