The confident wrong answer costs more than I don't know

Across hundreds of interviews, the most expensive sentence I hear is a wrong answer delivered with total confidence. Here is why it scores worse than honest uncertainty.

An interview loop is not a quiz. It is a simulation of working with you. When you answer incorrectly but confidently, you show me exactly what will happen in a code review, an incident, an architecture meeting: you will assert, others will believe you, and the error will ship.

When you say I have not used that in production, here is how I would verify, you show me the opposite: someone whose claims can be trusted because they are calibrated.

The practical version: for every topic you prepare, prepare three layers. The answer. Why you would choose it over the nearest alternative. And the conditions under which you would not choose it. That third layer is what senior sounds like, and almost nobody prepares it.

Definitions test memory. The loop grades judgment. Prepare for the exam that is actually being run.