What does it mean that confirmation bias operates in real time?

You unconsciously seek and emphasize evidence that confirms your existing beliefs.

Example: A senior engineer says 'the latency spike is definitely a database issue' and then spends forty minutes reading only database logs. The actual cause — a misconfigured load balancer — sits in plain view in the network dashboard they never opened. They weren't lazy or incompetent. Their belief selected which evidence counted as evidence.

Try this: Pick a belief you currently hold with high confidence — about a colleague's competence, a technical decision, a political position, anything that feels obviously true. Set a five-minute timer and write down only evidence that contradicts that belief. Not evidence you then rebut. Evidence you let stand. Notice how your mind resists. That resistance is confirmation bias operating in real time.