Tell me about a time you disagreed with a colleague or architect about a design. How did you handle it?
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Use your own real story. A model answer, STAR shaped: a colleague wanted to stretch a server VLAN between our two data centers for VM mobility, and I thought it would join both sites into one failure domain. We agreed the requirement first (failover for three applications), wrote down criteria together, and I built a small lab comparison. We presented both options with risks to the architect. The result was DNS-based failover for two apps and a limited, controlled layer 2 extension for the third, and the criteria template became our standard for design reviews.
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What the interviewer is testing
Whether you argue with data and requirements instead of opinions, whether you listen, and whether you can commit to a decision you did not prefer.
The model, step by step
- Situation: a design review for data center failover. My colleague proposed stretching the server VLAN between sites.
- Task: reach a decision that the network team and the application team could support.
- Action: I asked what the real requirement was and learned it covered only three applications. We agreed the criteria before arguing about solutions: failover time, risk, cost and effort to run. I tested both approaches in the lab and shared the results with my colleague before the meeting, so nobody was surprised in front of the architect.
- Result: two applications moved to DNS-based failover; the third got a narrow extension with storm control and a written plan for an interconnect failure. The relationship stayed good, and the criteria template is still used.
- Lesson: agreeing on criteria first turns a debate about opinions into a comparison.
If you lost the argument
That is a fine story too. Show that you raised the risk clearly, accepted the decision, helped make it work and documented the risk.
Traps
- Making the other person look foolish. Interviewers picture you doing it to them.
- A story where you were right about everything and learned nothing.