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Eli Fitch

Sr. Web Application Engineer at Mapbox


Perceived performance: The only kind that really matters
Thursday 11:50 - 12:40
Web performance
Cognitive psychology

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Web performance has made incredible strides in the last few years, which has presented developers with a new problem: How do we efficiently improve our app’s performance now that we’ve plucked the low hanging fruit from the vine? How do we make an API driven app faster when the performance bottleneck are API requests? The answer is directly manipulating users' perceptions in order to make our projects *feel* faster than they really are.

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 this talk, Eli will discuss the psychological basics of how people sense time, and how to use this understanding to create experiences that feel fast, tactile, and create the illusion of speed. He’ll break down real world, actionable guidelines on:

  • When it makes sense to focus on perceived performance over outright speed
  • How to turn the difference between active and passive mental states to our advantage
  • How to make "fake" progress bars feel genuine
  • How to cleverly craft animations to make loading seem faster
  • When to use unconventional event listeners to increase perceived speed
  • Predictive preloading: The art of anticipating user behavior and loading assets just in time

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Eli Fitch is a front end developer with a passion for web performance, animation and all things 3D. He works on creative tools to design expressive maps at Mapbox, a startup in his hometown of Washington, DC. He also organizes the DC CodePen Meetup, and dabbles in design, 3D art & game development.  When not sat in front of a computer, he restores his perpetually broken stable of 70s motorcycles and attempts to keep his historic row-house from collapsing in on itself like a dying star.