Your interview is a budget, and most people overspend early

Most candidates walk into an interview without a plan for the one resource they can't get back: time. They spend twenty minutes lovingly setting up the context of a problem, then realize the interviewer's notes have gone quiet and there are six minutes left for the part that actually gets scored.

Treat the hour as a budget. Before you ever sit down, decide roughly how the time should split across the phases of the conversation — context, your actions, the outcome, and questions — and rehearse hitting those marks. In a behavioral round, the expensive mistake is almost always the same: overspending on the situation and underspending on what you did and what changed because of it. The setup is cheap; the interviewer can follow a one-sentence frame. Your decisions and your impact are what they're buying.

The fix isn't to talk faster. It's to know, going in, that “while we were at X we hit problem Y, which caused Z” is a complete setup — and that everything after it should be you. Build your own time budget for each interview type. Then practice living inside it, because the version of you under pressure will always want to spend more on the comfortable technical setup than the budget allows.