How to reduce the First Input Delay? By cutting the code down, making the browser execute it during idle periods and routing the most expensive tasks to Web Workers.

The bittersweet consequence of YouTube’s incredible growth is that so many stories will be lost underneath all of the layers of new paint. This is why I wanted to tell the story of how, ten years ago, a small team of web developers conspired to kill IE6 from inside YouTube and got away with it.

Native lazy loading is coming to the web. Since it doesn’t depend on JavaScript, it will revolutionize the way we lazy load content today, making it easier for developers to lazy load images and iframes […] learn how it works and how you can progressively replace your JavaScript-driven lazy loading with its native alternative, thanks to hybrid lazy loading.

Improving third-party web performance at The Telegraph

Another “gotcha” to look out for is that software supporting HTTP/2 is not fully mature yet. Although it is getting better all the time, software for HTTP/2 just hasn’t had enough time to become as mature and solid as existing HTTP/1.1 software.

"A set of questions and tasks to guide you on your speaking path. Answer these to up your chances of being selected to speak at a conference or event."

"Web performance can mean the difference in someone being able to get what they need from government or abandoning their task completely."

Animation Performance 101: Measuring with Dev Tools

"After a lot of trialing we have settled (for now at least) on moving our rendering tier to React and Emotion. This will doubtless generate a new set of challenges, but we expect that they should at least solve the set we have right now."

"Every bit of JavaScript you add to a site is a potential way in for a hacker. This is doubly true if that JavaScript is hosted by someone else, such as on a public CDN. Subresource Integrity is a browser feature you can use to make sure that the code being used is exactly what you intended."

"For most developers, code caching should “just work”. It works best, like any cache, when things stay unchanged, and works on heuristics which can change between versions. Nevertheless, code caching does have behaviors that can be used, and limitations which can be avoided, and careful analysis using chrome://tracing can help you tweak and optimize the use of caches by your web app."

"Our hypothesis was proven. The simpler and faster web player outperformed the old web player in all key metrics."

Shows how different HTML attributes behave in commonly used screen readers.

"ResourceTiming exposes accurate performance metrics for all of the resources fetched on your page. You can use this data for a variety of scenarios, from investigating the performance of your third-party libraries to taking specific actions when resources aren’t performing according to your performance goals."

JavaScript Loading Priorities in Chrome