Perceived performance: The only kind that really matters

Perceived performance, in the end, is the only performance that truly matters. If what we make doesn't feel fast, then no amount of optimization counts. Eli Fitch breaks down the psychology of how users perceive time and how we can combine that knowledge with clever use of animation, unconventional event listeners, and predictive design to make our experiences seem faster than they actually are.

We all want our projects to be fast. We agonize over JavaScript bundle sizing, our chosen CSS preprocessor’s impact on stylesheet bloat, caching schemes, and more as we head down the performance rabbit hole. But here’s the rub: doggedly chasing kilobytes isn’t an efficient way to improve your project’s performance if users aren’t be able tell the difference. At the end of the day, perceived performance—what users feel and experience while using your app—is what truly matters. This isn’t easy. Humans are imprecise beings, and how we perceive the world around us is fraught with fascinating quirks. Improving perceived performance is likewise an incredibly challenging prospect. If people don’t perceive time accurately, how can you possibly hope to build to meet this nebulous standard? In order to make experiences that feel satisfying, you need to understand the basic psychology behind how humans perceive time in the world around them. This opens the door to a universe of possibilities and a deeper connection with the users we all serve. Eli Fitch discusses the psychological basics of how people sense time and explains how to use this understanding to create experiences that feel fast, tactile, and satisfying. Topics include: