What do I recommend to a friend who's looking for an absolute-beginners CSS intro? "How do I make margins", that sort of thing?

"The difference between bandwidth and leadership is scalability" https://experiments.randomthebook.com/LinkedInWisdom/Index.html

Home. Sleep. No #perfnow day 3. I'm sorry.

If you don't want a firehose of modern insights into web performance cluttering up your timeline, don't follow @perfnow.nl

No lies detected.

Right in time for the conference!

If you don't want a firehose of modern insights into web performance cluttering up your timeline, don't follow @perfnow.nl

And #perfnow has started. A live stream is available via https://perfnow.nl/live-stream.html

Ticket. Bought one last week. Hotel. Check. Fuckingly annoying Easyjet site survived. Check. I think. So it seems I'm going to #ffconf . Will you? https://ffconf.org/2025

Two of our attendees were refused a visa 😞 Still, that means we have two tickets left if anyone wants to come at this late stage. perfnow.nl/tickets.html

Three tickets left. Buy now.

Schedule schedule on the wall, who has the best line-up of them all? perfnow.nl/schedule.html

OK, we're down to our last tickets. There's still room for people to join performance.now() on 30th and 31st of October (in two weeks and a bit), but it's time to decide. https://perfnow.nl Last tickets at https://perfnow-2025.eventstack.shop

OK, we're down to our last tickets. There's still room for people to join performance.now() on 30th and 31st of October (in two weeks and a bit), but it's time to decide. perfnow.nl Last tickets at perfnow-2025.eventstack.shop

Left picture: the pro-Palestina demonstration last weekend. Right picture: the anti-immigration demonstration this weekend. Both on the same place about 1km from my house. Arrests last weekend: 0. Arrests this weekend: dozens.

Anyone who works on browsers, or might know of where there might be information on this: I'm pretty sure that a few years ago I heard that browsers (maybe it was a specific one?) were optimizing custom props declared on the :root, and which didn't change values. Was this a thing? Is it still true?

In the tram I sat opposite two girls, who did some web design and were clearly about to become a couple. It was very sweet … and then one girl tried to impress the other by naming Adobe products… I hope someone can explain the importance of Adobe products in modern lesbianist lifestyles.

Today I went to the university library for the first time in close to 25 years in order to pick up my library card. They couldn’t help me because the printer broke down. And tomorrow they’re closed due to the official opening. It’s like coming home, except with more bureaucracy.

... and if I were to ask you "Who would you like to see speak at CSS Day 2026", what would your answer be? Name as many names as you like. I'd like to hear about people who aren't that well known yet.

performance.now() is coming! Every byte shipped carries a carbon cost. @inesakrap.bsky.social will present insights from the Sustainable Web Guidelines that result in a site that is not only fast, but also green and responsible. perfnow.nl/speakers.html#ines

Oh, good tip. Go here: https://www.linkedin.com/mypreferences/d/settings/data-for-ai-improvement and turn off "Data for Generative AI Improvement" on LinkedIn.

performance.now() is coming! LCP and INP measure loading and responsiveness of entire pages – but same-document soft navigations were much harder to measure. Until now! Michal Mocny will explain how new Performance APIs make this possible. perfnow.nl/speakers.html#michal

performance.now() is coming! LCP and INP measure loading and responsiveness of entire pages – but same-document soft navigations were much harder to measure. Until now! @mmocny.com will explain how new Performance APIs make this possible. perfnow.nl/speakers.html#michal

performance.now() is coming! As tooling improves, is performance testing becoming any easier? @csswizardry.com, who spends every day auditing client projects,, thinks confusion has increased. Let's ensure that every test we run has a purpose and gives us useful data. perfnow.nl/speakers.htm...

Today our congregation of faithful will sing the psalm What An Incredible Piece Of Shit Gimp Is

performance.now() is coming! @tammyeverts.com asks a seemingly-simple question: How Fast Is Fast Enough? She'll touch on questions — ranging from neuroscience to business metrics — to get you thinking about how you create, measure, and report your performance goals. perfnow.nl/speakers.htm...

justify-self on arbitrary elements is Chrome only for now, correct?

Re-aligning my business goals ... stand by ...

performance.now() is coming! Signal-based fine-grained reactivity works great, but @rich-harris.dev feels there's more to performance than updating the screen at 60 fps. We'll learn about new approaches that help you build fast, reliable, data-efficient apps. perfnow.nl/speakers.htm...

A car just went by that said "Transforming Future Coolness". It sounds great, but I don't know what the product would be. Or is it an experience?

performance.now() is coming! @marcysutton.com explains how designing for accessibility contributes to better experiences, and why subtle choices — like which elements receive focus — lead to better products. She’ll also talk about the legal context in Europe. perfnow.nl/speakers.htm...

performance.now() is coming! @ethangardner.com will offer practical tips on presenting engineering data as a competitive advantage, a revenue driver, and a tool for enhancing user experience to help make performance optimization a strategic priority. perfnow.nl/speakers.htm...

performance.now() is coming! @webx.bsky.social [] will explain how he built a Performance AI assistant and agentic workflow on top of a fork of Chrome DevTools. Few AI systems can reason with the complex reality of performance data. Learn how to solve that. perfnow.nl/speakers.htm...

performance.now() is coming! @adevnadia.bsky.social will provide a deep dive into the new React Server Components. How does the app render in the browser? What are their performance implications? How do they compare to traditional SSR and CSR techniques? perfnow.nl/speakers.htm...

onDomContentLoaded, Firefox recognises document.querySelector(':target'). Chrome and Safari do not.

performance.now() is coming! The night before the conference, 29th of October, Mozilla organises performance.sync(), the pre-meetup where you can meet your peers to mentally prepare for two days of information overload. They're also looking for a few people to present. https://luma.com/ziykhh4y

performance.now() is coming! The night before the conference, 29th of October, @mozilla.org organises performance.sync(), the pre-meetup where you can meet your peers to mentally prepare for two days of information overload. They're also looking for a few people to present. luma.com/ziykhh4y

First time I prepare a D&D session entirely with Flee Mortals monsters. Let's see how they compare to MM-2024 monsters.

Status: hangover slowly disappearing. Don't ask.

performance.now(), the web performance conference, 30th and 31st of October, Amsterdam. Single track, the best speakers in the industry, plenty of your performance-mad peers around to have fascinating conversations. What's not to like? https://perfnow.nl/

performance.now(), the web performance conference, 30th and 31st of October, Amsterdam. Single track, the best speakers in the industry, plenty of your performance-mad peers around to have fascinating conversations. What's not to like? Let's introduce our speakers ... perfnow.nl

TIL: You can put a text input inside a <button>. Works absolutely fine.

Wow. I just logged back into Amazon Prime and had to reset my password. That went fine, but now I got one of those warning mails about someone doing something to your account, but it's from amazon.co.uk (which has nothing to do with primevideo.com in NL, I'd say)

“I don’t like CSS” is coded speech for “I never learned CSS”

Hype is a business tool. Too many #UX folk don't know about the Gartner Hype cycle. Even those that do don't understand how it's being used to manipulate us, making our discussion of #genAI so complicated and scary. This is my attempt to calm things down a bit. jenson.org/hype/

Last night in Greece. Back home tomorrow.

Reading the saga of Ragnar Loðbrók. Fun fact: the king of Sweden had a cow that could cast both Confusion and Fear, provided enough sacrifices were made to it. Unfortunately the saga doesn't say what kind of sacrifices.

At Schiphol for my holiday flight to Greece. Despite the holiday throngs I nearly equalled my record of 50 minutes home to gate, mostly because there was no security queue.

Explained the basics of SEO to a third-generation comics seller (and marketing student)