Latency is a design material
Speed is not merely a benchmark. It shapes whether a tool feels direct, understandable, and respectful.
People notice the gap between an action and its response long before they can name it. A quick acknowledgment tells us the system heard; a stable layout tells us it has settled.
Feedback before completion
Not every task can finish instantly. Good interfaces separate acknowledgment from completion: first confirm the action, then show honest progress, and finally make the result unmistakable.
Performance work is therefore partly communication. Reduce the delay where possible. Where it remains, explain it without demanding attention.