You cannot cover everything deeply in minutes. Choose wisely:
Go deep when:
- The component is central to the problem (fan-out for Twitter, matching for Uber)
- Your interviewer asks follow-up questions
- You have unique insight or experience
Stay high-level when:
- The component is standard (basic load balancing, standard caching)
- Time is running short
- You're less confident in the details
A good rule: in-depth exploration of - minutes, - medium dives of minutes each, rest high-level.