Each question below includes what the interviewer is actually testing. That matters more than the answer itself — once you know what is being probed, you can answer from your own experience instead of reciting someone else’s script, which is obvious to everyone in the room.
Whether you can reason about tradeoffs, or only implement decisions others made. This is the single most common mid-to-senior discriminator.
Name the constraint that drove the design (read-heavy? strict consistency? tight budget?), then two options you rejected and why. Interviewers remember the rejected options — that is what proves you actually chose rather than defaulted.
Ownership and blamelessness. Candidates who have never broken production have usually never had real responsibility.
State the blast radius honestly and in numbers, then move quickly to detection, mitigation, and the systemic fix. Ending on "we added a test" is weak; ending on "we made the class of bug impossible" is strong.
Business judgment. Juniors treat all debt as bad; seniors price it.
Tie it to a rate of interest — debt that slows every future change is urgent, debt in a stable component nobody touches is not. Give a real example where you deliberately left debt alone.
Systematic method under uncertainty versus flailing.
Show a narrowing loop: confirm it is real (metrics, not vibes), isolate the layer, form one hypothesis at a time. Mention what differs in prod — data volume, cold caches, noisy neighbours, network topology.
None of this matters if your resume is filtered out first. The most common cause is not a weak background — it is a document that screening software cannot read correctly, or one that lists duties where it should show results.
Check your resume against software engineer keywords or run a full scan. Both are free and take about three seconds.