Denys Mishunov: Why Performance Matters - JSConf Budapest 201

Load a page in less than a second; reduce the number of server requests; keep your CSS and JS merged and compressed to keep them under 50 kilobytes” – these are just a few among technical solutions and recommendations we are getting in the industry to tackle performance issues. But there is one catch – your users don’t care about absolute values in kilobytes, milliseconds and number of requests.

Performance is not about Mathematics. Performance is about Perception. Perception is what makes a site with a very few requests nevertheless feel slow, while a site that delivers search results during tens of seconds can feel fast enough for your user. User’s perception of your website’s speed is the only true performance measure.

This talk is about perception, neuroscience and psychology. The time is ripe to understand performance from the user’s perspective.

[MishaAmashukeli]

Most of these techniques are not about perception - they are just normal mathematically measurable ways to increase performance. Streaming and prefetching are not about perception, they are used in software and hardware to increase performance even when no human is involved. The only example that actually had anything to do with perception was the airport story.