How performance data is collected at Wikipedia

"Whenever performance testing AMP, keep in mind that a test from origin will include potentially suboptimal server settings like bad cache headers or missing image optimizations. Also the biggest speed gain (near instant load through prerendering) will not be reflected in commonly used performance tools and metrics."

"IntersectionObserver is a very straight-forward technology. It has a pretty good support in the modern browsers and if you want to implement it for browsers that still (or won’t at all) support it, of course, there is a polyfill for that. But all in all, this is a great technology that allows us to do all sorts of things related to detecting elements in a viewport while helping to achieve a really good performance boost."

"Quantum Render (or WebRender) is a major graphical system overhaul that’s coming to Firefox this year, and it promises hardware-accelerated painting of web content with huge performance wins."

No more requirejs calls in network!

"With the DNS prefetching flag in Google Chrome on Android enabled, Chrome scans the page for clickable links and resolves the URLs to IP addresses. By the time you head to any of the pages, their addresses will have been returned to your device, mitigating any DNS speed issues — the only bottleneck will be your own connection. (Optionally, it will use your device’s own DNS servers and won’t touch Google’s unless you want it to.)"

"Some of these technical aspects are often overlooked. Also, don’t be afraid to change things around and set yourself up to test several variants of code on your website."

Just because your site isn't for emerging markets, doesn't excuse you from web performance optimisation

Hell is other people’s JavaScript.

TL;DR : Reduce the weight of your files by using optimization strategies that depend on the content and purpose of your videos ; Optimize streaming by encoding your videos to serve metadata as soon as possible ; Propose alternatives to MP4, such as WebM.Be careful with autoplay, consider dedicated solutions for Full HD and don’t hesitate to hide videos when needed.

"webpack is a fantastic, versatile, tool that does not need to cost the earth. These techniques have helped us reduce our median build time from 170 to 17 seconds and, while they have done much to improve the deployment experience for our engineers, they are by no means a complete work."

JavaScript a un coût (The Cost Of JavaScript). Je continue de préférer, tel un vieux développeur que je suis, à construire des coquilles. Je ne dénigre pas le JavaScript ou les applications, mais quand on code un site qui va être chargé par tous types d’utilisateurs, il est important de prendre en compte les cas de faibles connexions.

Using page speed in mobile search ranking

"Third-party scripts are probably the #1 cause of poor performance and bad UX on the web. It's no wonder things like AMP exist. The fact that it disallows third-party scripts is probably the largest contributor to it making sites fast. Controversial as hell, though, in its other choices."