Scoping the Question

When an interviewer says “design a messaging app,” first agree on which part of messaging to cover. Opening a conversation, reading history, and sending text can provide a useful discussion. Calls, media, search, and group administration may not all fit in the same session.

A good scope keeps the important technical problem while limiting unrelated work.

1. Confirm the system boundary

Ask:

“Should I design the mobile client, the client and API, or the complete system? If an API exists, may I propose changes?”

These are separate questions