Tell me about a time you needed someone to change how they worked and had no authority to make them. What finally worked?

Without authority, influence has to run on something real: credibility, evidence, or the other person's own interests. Asking what finally worked makes the candidate name their actual currency — which is how they'll operate anywhere most people don't report to them.

• What did they care about that you connected to?
• What did you try first that didn't work?
• Did the change stick once you stopped paying attention?

The other person's interests understood and worked with, an approach adjusted after a first attempt failed, and a change that held without enforcement — plus honesty about the goodwill it cost.

Influence that was actually escalation in disguise, one pitch repeated louder, or compliance mistaken for agreement — the change died as soon as they left the room.