Performance is a product feature

Performance is usually discussed as an engineering metric, but users experience it as product quality. A slow interaction feels uncertain even when the interface looks polished.

The best improvements often come from reducing work rather than optimizing work: smaller payloads, fewer dependencies, predictable cache boundaries, and UI states that communicate progress immediately.

Treating performance as part of design creates better tradeoffs. The question becomes not only whether a feature works, but whether it feels dependable in real-world conditions.