Your project did not achieve its goal. What would you change?

Be specific about the cause, separate what you could control from what you couldn't, and give a concrete improved plan.

Model answer.

What the interviewer wants. Engineering is full of results that fall short of the target. The interviewer is testing your analytical thinking (do you understand why?), honesty (do you admit it?), and judgement (would you do better next time?).

Structure

1. State the target and the actual result honestly, with numbers if you have them.
2. Explain the root cause technically: what you found or suspect, and how you checked.
3. Separate controllable from uncontrollable factors without making excuses.
4. Give a specific improved plan.

Sample answer (replace with your real project)
"Our target was [e.g. to keep the output voltage of our converter within ±2% under load changes], but we only achieved [e.g. about ±5%].

When we investigated, we found [root cause, e.g. the inductor we used was saturating at higher currents because we chose it based on its inductance value without checking its saturation current rating]. We confirmed this by [test, e.g. observing the inductor current waveform on an oscilloscope, which showed a sharp peak at higher loads].

Part of it was a component availability issue, but mostly it was a design-review gap on our side: we didn't check all the ratings early.

If I did it again, I would [improvements, e.g. calculate peak currents first and choose components with margin, simulate with realistic component models, and test at full load early instead of at the end]."

Why this works. It shows technical understanding, accepts responsibility, and gives a practical improvement.

Tips

• If you do not know the exact root cause, say so and explain your best hypothesis and how you would test it.
• Do not inflate the results on your resume. If the resume says "achieved ±2%", that is a problem.

What to avoid

• Blaming the guide, the lab or the budget for everything.
• Vague causes like "there were some technical issues."

Likely follow-up. A technical question on the cause you mentioned, such as "What is inductor saturation and how does it affect the circuit?" Be ready to explain it.