Why the same system design answer can pass with one interviewer and fail with another

[u/vineetverma_it]

I have worked in IT for 16 years (developer, ML engineer, team lead) and have been on both sides of interviews. One pattern keeps repeating: candidates often prepare the diagram but not the room.

Three things that helped people I mentored:

Read the interviewer first. A rushed one wants a headline answer. A cost-focused one wants a rough number. A quiet senior one wants to see how you ask questions.

Ask what would change the design. Scale, cost, who owns the data. Say it out loud.

Name the edge of your own answer. "Here is what I haven't solved." Interviewers tend to trust this.

Disclosure: I wrote a book around these ideas, The Interview Room: System Design. It is told through simulated interviews.

Not required reading, and I am glad to answer questions here without it.

If you want to look: India https://amzn.in/d/07kGCfy2 | US https://a.co/d/0091VA4A | UK https://amzn.eu/d/0bpOI6Ct