People, not projects
What's been your most successful project?
What's an insight you obtained from talking to a customer?
Tell me about a time when you resolved a conflict between two people.
These are common behavioural questions asked in interviews. Quite a lot of people end up explaining the ins and outs of the situation — the project specifics, the customer insight, or the nature of the conflict.
That's not what the interviewer is looking for. They are trying to understand how you show up... how your values are reflected in your actions and decisions.
Instead of spending time on the details of what led up to the situation at hand, talk about the people, their motivations, the problems you identified and solved, and what you learned in the process.
Behavioural questions are about people, not projects.