In this talk, we’ll take a look at unruly or uninvited (third-)party guests: how to detect them, how to audit them, and how to manage them. We’ll also look at the different tools available to help us stress-test and quantify the overhead these third parties bring, and what that means for users and businesses alike.

There is a clear pattern of environmental properties having the worst correlation: Effective connection type, device memory, available CPU, page transfer size. This might suggest that users are aware of their device, network quality and page size (small vs big article in Wikipedia's case) and adjust their expectations to those factors.

Our current generation of frameworks makes off-main-thread architectures hard and diminishes its returns. UI frameworks are supposed to do UI work and therefore have the right to run on the UI thread. In reality, however, the work they are doing is a mixture of UI work and other related, but ultimately non-UI work.

HTML and CSS are just more resilient than JS. […] Use polyfills, use progressive enhancement: use JavaScript responsibly.

[…] we need to change the way we think about performance and think of it as part of the process instead of an extra. The best way to do this and make it part of the culture of our teams is to try to find a way to include it as part of our planning.

C’est un bon début mais il ne faut surtout pas se limiter à ce type de test. Il faut poursuivre par des tests manuels réalisés par des auditeurs en accessibilité, et idéalement compléter avec des tests d’utilisateurs en situation de handicap.
[…] Quoiqu’il en soit, il est important de garder en tête qu’il n’existe pas d’outil magique concernant l’accessibilité. Il y a juste des outils (et c’est déjà pas mal) qui permettent de faciliter le travail d’un auditeur en accessibilité.

• Risks: slowdowns and outages, service shutdowns, security vulnerabilities
• Penalties : network negotiation, loss of prioritisation, caching

All of that for the sake of the cross-domain caching? Please, self-host your static assets.

… But I couldn't teach anything without first teaching them how the browser work. None of it made any sense unless you have a pretty good knowledge of the inner working of the browsers.
So really, when we're talking about performance what we're really talking about is making the browser happy. […] And this is not something that we're used to be talked about.

This is a small explainer that I built for a talk on web fonts and performance. […] For example, if you're rendering the main body text on a site, you should use font-display:optional.

As a matter of fact, the Time To Interactive does not measure how long it takes for a page to become interactive, it measures how long it takes to be sure, regarding the conditions, that a interactivity can happen in a satisfactory way, for at least 5 seconds.

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."