What should I ask in a reference check?

Closing specific gaps, not rubber-stamping a decision. Before the call, look at the scorecards and the structured interview questions each round used, then write down the two or three things nobody assessed confidently. Perhaps the candidate described leading a project and you never established how much they led. Perhaps a competency scored in the middle with no evidence attached. Those become your questions. A reference call with no agenda produces vague praise and changes nothing, which is why so many teams treat the step as a formality. Run it as an evidence-gathering exercise with named uncertainties and it becomes one of the cheaper signals available late in a process, particularly for senior hires where the cost of being wrong is high.

Behavioural and specific. What did they own, and what did you own. What would you have them do again immediately, and what would you not put them on. Tell me about a time they disagreed with you. How did they respond to feedback that landed badly. What conditions bring out their best work, and what conditions do not. Would they be one of the first people you hired again into a similar role, and why. Notice the pattern: each question asks for a concrete instance rather than an assessment. Vague questions produce vague answers. Also listen for hesitation and for what the referee carefully does not say, which is often the more informative part.

A former direct manager first, then someone who worked alongside them daily. A direct report as well if you are hiring a leader, since that view differs most from the manager's. Candidates supply their own referees, which biases the sample, so be explicit about the relationships you want rather than accepting whoever is offered. Back-channel references gathered through your own network without the candidate's knowledge are common in some markets and considered a breach of trust in others, and they carry data protection implications that vary by country. If you use them, be honest with yourself about the risk, and never let an unverified second-hand comment override documented interview evidence.

When it produces specific, consistent evidence that contradicts something the interviews concluded. One lukewarm referee is weak signal. Two independent people describing the same pattern, with examples, is strong. Weigh what you hear against the role: someone who struggled in a chaotic environment may be an excellent hire into a structured one, and the referee has no visibility into your context. Write your notes into the candidate record in your hiring software alongside the scorecards so the decision trail is complete. If a reference makes you pause, the right response is usually another conversation with the candidate, not a silent rejection. And if two referees describe the same strength you doubted, treat that as a reason to revisit your rating rather than as noise.