Share the specific techniques you used and the measurable outcome. Did they ship independently? Get promoted? Solve harder problems?
Look for patience, structured approach (pairing, code reviews, setting achievable goals), and genuine investment in others' growth. Strong answers include measurable outcomes: "After three months of pairing, they started leading features independently." Red flag: candidates who only helped when asked.
Critical for senior roles. Candidates who cannot mentor are not truly senior regardless of technical skill. Ask follow-up: "What was the hardest part of mentoring them?"