How to Answer: “What is your greatest professional achievement?”
A complete guide to answering this common interview question — including what interviewers are really looking for, practical tips, and a worked example answer.
What interviewers are really asking
Choose an achievement that is relevant to the role, quantifiable, and shows your personal contribution clearly. Use STAR. Make sure the achievement is genuinely impressive — not something most people in the role would have done.
Tips
- Quantify everything you can — numbers make achievements real.
- Make your personal contribution clear, not just the team's.
- Choose something relevant to the role you're applying for.
- Show the context — why was this hard?
- Don't be falsely modest — own your success.
Example answer
Sample response
“In my second year as a data analyst, I identified that our churn model was systematically mis-scoring a segment of customers — flagging them as low-risk when they were actually very high-risk. I rebuilt the feature set, retrained the model, and worked with the customer success team to pilot proactive outreach to this segment. Over the following six months, churn in that segment dropped by 34%, which translated to roughly £1.2m in retained ARR. That's the work I'm most proud of because it started from my own curiosity rather than a brief.”
Adapt this to your own experience — never use any example answer verbatim.
Use the STAR method
Structure your answer as: Situation (brief context), Task (your specific responsibility), Action (what you personally did), Result (the quantified outcome). Most strong interview answers follow this pattern.
Full STAR method guide