Performance Is a Feature

Users don’t forgive slow products. No amount of beautiful design can compensate for an interface that feels sluggish. Performance isn’t an engineering concern; it’s a design concern.

The Perception of Speed

What users feel isn’t the same as what actually happens. A 200ms perceived delay feels instant. A 500ms delay feels noticeable. Anything over 1 second feels broken.

Optimistic UI. Update the interface immediately, then confirm with the server. This makes products feel instant even when they’re not.

Skeleton screens. Better than spinners because they show the user what’s coming, reducing perceived wait time.

Design Decisions That Impact Performance

Every image, every animation, every custom font you add costs something. The question isn’t “can we afford this?” It’s “is this worth the trade-off?”

The fastest interface is the one that doesn’t load at all. Progressive enhancement means your core experience works before your enhancements arrive.