Ryan Trimble
Stage at CSS Day in Amsterdam, on screen there is a slide that says CSS Day Welcome to our 9th edition

Visiting Amsterdam for CSS Day

Front End Development

Judging from my London Calling and Vue Conf Recap posts from earlier this year, you might get the impression that I travel a lot. That is not the case, just this year happens to be the year we (my wife and I) decided to branch out and explore the world. In fact, before this year, I had never even been on an airplane.

This time we traveled to Amsterdam, The Netherlands, to attend CSS Day — which I found out is the only CSS-specific conference in the world now.

First night in Amsterdam

After a long, nine(-ish) hour total flight from Baltimore to Iceland, then Iceland to Amsterdam, we checked in at our hotel and took a power nap before going out to explore the city a bit.

We originally had booked an upper-floor room as I was hoping to get a good view of the canals, however, the only room the hotel had available to check in early for was a basement-level room. I was disappointed for a moment until we saw the room and realized we were nearly level with the canal which still provided an incredible view.

View from our hotel at canal level

On the first night, we kept things fairly low-key by taking a walk down some streets and checking out some of the many canals. For dinner, we tried a local automat fast food chain called FEBO. They have a wide variety of items to choose from at FEBO, all inside a vending machine-type wall. We tried fries, croquettes, and burgers all for a few euros each, all pretty good!

First day of CSS Day

The first day of CSS Day! The event was held in the Zuiderkerk, a 17th-century church that is now being used for events such as developer conferences. The Zuiderkerk was about a ten-minute walk from our hotel, which was perfect. We got there early and watched as folks began to arrive.

For breakfast at the conference, we had coffee with croissants and jam. The conference recommended we keep to the “Pac-man” rule of always leaving space in groups for more people to join, which was a great way to meet new folks!

I had the wonderful opportunity to meet my friend Kilian Valkhof who makes my favorite developer tool, Polypane. I’ve been chatting with Kilian for a while through the Frontend Horse community and it was so nice to meet him in person. A few other great folks I met included James Basoo (who I connected with on Mastodon just before the conference) and had a lovely discussion with Liesbeth Smit and Paul Van Buuren in which we talked about our embarrassing old screen names and websites.

Day one of CSS Day had Adam Argyle as the Master of Ceremonies. Setting <aside> his use of corny developer puns, Adam has a great personality for this type of thing and kept things exciting.

Una Kravets

Una Kravets kicked off talks with her presentation on The State of the CSS Community. This was super exciting to see all the new features of CSS shipping from browser vendors, as well as many new features proposed by the Open UI group being considered.

Una is right, this is a much different time for CSS, I still remember when new CSS and browser features took forever to get implemented. It’s a CSS Revolution!

Hidde de Vries

Next up was Hidde de Vries, who talked about a topic I recently researched quite a bit for my post The Popover API is Exciting, sort of - the Popover API.

Hidde walked through how the Popover API works as well as provided some excellent examples as to when to use Popovers and when to use <dialog> elements.

One of the things I was concerned about in my post was browser support for the Popover API and luckily it seems that this feature will be shipping in Safari 17 later this year, which is a great sign for adoption.

Léonie Watson

When I looked through the line-up of speakers and topics, one that piqued my interest was from Léonie Watson on CSS Speech, mainly because I had never heard of it. Well, it turns out that is because it doesn’t quite exist yet. During breakfast, I was chatting with Jeremy Keith who said Léonie’s talk is a rallying cry to gather support for this concept.

Léonie described how with voice assistants, such as Siri or Alexa, there are ways to manipulate the voice to give it more character using something called SSML. With SSML, you can do things such as adjust the voice as if it were a font, change the pitch of the voice, as well as adjust the rate of speed at which the voice is read. Essentially Léonie is asking: why isn’t this a thing in CSS?

Well it turns out, this was in the CSS spec at one point, but was dropped for seemingly unknown reasons.

The main benefit to this would be for assistive technologies such as screen readers, where designers and developers would have the opportunity to provide better experiences for those listening to their content.

This was such an interesting concept and now I’m on board for this to be implemented.

Sanne ‘t Hooft

Sanne ‘t Hooft’s Tinkering at Night talk turned out to be another topic I am not familiar with but was super interesting to see what is capable nowadays with CSS. Sanne demonstrated the superpowers of the CSS trigonometric functions to create stunning animations and potential UI implementations.

As someone who doesn’t math very well, this admittedly went a bit over my head, however, I was still able to appreciate these new capabilities of CSS. I was never great at math in school, but it is something I have gotten better at understanding while learning more practical applications for math in programming, this talk inspired me to add these trigonometry features to my list of things to try out.

Patrick Brosset

CSS selector performance is something I don’t think about too much and luckily Patrick Brosset shared that, in most cases, this is fine. However, when it does become an issue, it is good to know how to troubleshoot potential problems.

Patrick gave several great tips on how to utilize the browser developer tools to track down problems, as well as potential examples of when these issues might occur.

Heydon Pickering

If you are familiar with Heydon Pickering and his Webbed Briefs videos, this talk was very much in the same vein — which is a great thing!

Heydon spoke about scoping in CSS and how everything in CSS is some form of scoping. He discussed how JavaScript frameworks approach scoping and talked about the @scope feature that will eventually be making its way to browsers.

Hilarious and informative, and absolutely one of my favorite talks from the conference!

Heydon Pickering on stage at CSS Day

Sophie Koonin

Sophie Koonin’s talk was a walk down memory lane for me as she described a very familiar start to her web developer journey by building websites on Geocities, learning HTML and styling in places like Neopets and MySpace.

Nowadays the web is, in general, a capitalist hellscape that lacks a certain charm that personal websites promoted back in the day.

Sophie is encouraging people to get weird with the web again and build more personal websites, experiment with things and see what can be done to make the web fun. This is especially true now where maybe getting off of social media networks and owning your data is becoming more important.

Sophie Koonin on stage at CSS Day

Final Day of CSS Day

The second and final day of CSS coincided with my birthday, which being at CSS Day was one of the best ways to celebrate. The conference continued being amazing with more amazing talks and meeting amazing folks.

One of those folks is another friend from the Frontend Horse community, Thomas Michael Semmler. Thomas was such a pleasure to meet and it felt like catching up with an old friend even though we had never met in person.

The Master of Ceremonies for the final day was Michelle Barker, who runs the CSS {In Real Life} blog. Michelle did a wonderful job announcing speakers and providing thoughtful input and questions in the after-talk question-and-answer sessions.

Miriam Suzanne

Container Queries are something that took some time for me to wrap my head around. Initially, I was confused as to what they did differently compared to Media Queries. I did manage to figure that out on my own, however, Miriam Suzanne’s talk on the topic further cemented to me that Container Queries have a lot more potential.

Miriam demonstrated the powers of containers and introduced me to container-style queries, which I have been playing with since getting back home. I can see myself re-watching this talk several times.

Also, after the talk, I asked Miriam if the premise of the talk “CSS Containers, What Do They Know?” was a reference to Bojack Horseman (one of my all-time favorite shows) and I can confirm that it was.

Umar Hansa

Umar Hansa presented on using modern tooling to help create and debug CSS. In his talk, Umar showed off many tips on using VS Code to its fullest, including using code snippets, shortcuts, and extensions. Umar also discussed other tools, such as artificial intelligence, to assist in writing code.

This is another talk I want to review as there were many great tips throughout the presentation and had my head spinning with possibilities.

Stephanie Eckles

One of the main reasons I wanted to attend this conference was for Stephanie Eckles as I think she has made the biggest impact on how I write CSS nowadays. I know Stephanie from the Frontend Horse community and was luckily able to attend her Modern CSS Workshop last fall through work.

Stephanie Eckles on stage at CSS Day

Stephanie is brilliant with CSS and has so much knowledge on the topic that it seemed difficult for her to contain it in just an hour-long talk.

It was great getting to meet with her in person as well and hanging out under the stairs with her and Thomas is one of my favorite memories from the conference.

Jhey Tompkins

I have been following Jhey Tompkins’ work on Codepen for a long time and his creative use of the medium absolutely carried over to live events.

Jhey demonstrated several ways to take something plain and turn it into a fun and memorable experience. The talk itself, for example, had a web page folks could visit and toss emojis onscreen with booming sound effects.

Cassondra Roberts

This is one of the talks that seemed to stick with me more than I initially expected it to. Cassondra Roberts detailed using CSS within JavaScript Web Components and the differences between the light DOM and the shadow DOM.

I have been digging into native web components since this talk, trying to piece together the things Cassondra taught me and mixing them with other things from the conference as well and it’s been super fun!

Bramus Van Damme

Originally this slot was for Jake Archibald to talk about the View Transitions API, which he helped pioneer. Since Jake left Google, Bramus Van Damme decided to fill in and give an excellent two-for-one talk on View Transitions as well as Scroll Driven Animations.

Over the holidays, I wrote an article for Stephanie Eckles’ 12 Days of Web project on the View Transitions API, so I had a familiarity with the topic and it was interesting to see how much has changed since then. Bramus demonstrated several great examples of how the View Transitions API can work with single-page applications and introduced a method for using them in multi-page applications (also known as websites).

Scroll Driven Animations are another exciting new feature that I’m excited to play around with. Looking at Bramus’ demo site for the feature, there appears to be a lot more potential here than I originally thought. Bramus also showed possible ways to combine Scroll Driven Animations with other features to perform Scroll Triggered Animations. It will be interesting to see how this gets finalized in Chrome and when other browser vendors adopt it.

I also got the chance to talk shop with Bramus a bit on the first day and it was great meeting him!

Manuel Matuzović

For the final talk at CSS Day, Manuel Matuzović walked us through his evolution of writing CSS over the years. Manuel made it his mission to keep up-to-date with the latest modern CSS with a project where he focused on a different topic each day for (over) 100 days called:


Manuel Matuzović on stage at CSS Day

Manuel’s process felt very similar to how I’ve approached learning new CSS concepts, typically focusing on one thing until I understand it. I enjoyed Manuel’s talk. He showed several modern techniques that I had not seen before, such as using container-style queries similar to how Sass mixins work.

Saturday in the City

While in Amsterdam, there were several things I wanted to check out, but had little time to see everything. Sights such as the Van Gogh Museum and the Anne Frank House were booked out a month in advance, so, unfortunately, did not get to see these. Even still, we did manage to pack a lot of sights in on the Saturday after the conference.


The Rijksmuseum is certainly a must-see if you are visiting Amsterdam. I never feel super excited about visiting museums for some reason, but I always lose my mind while I’m there.

Primarily the Rijksmuseum is an art museum of many of the dutch-masters such as Rembrandt and Vermeer.

Seeing Rembrandt’s work in person, such as The Night Watch, was incredible.

Outside of the Rijksmuseum with a banner depicting Rembrandt


The KattenKabinet (or Cat Cabinet) is a museum for all things cats. Many movie posters, advertisements, sculptures and paintings all depicting cat imagery are found all over the halls. They even had a quite serene garden outback containing even more cat-themed pieces.

One of the best and probably most obvious parts of the cat museum is that live cats are roaming around. This was certainly a highlight of the trip for my wife.

Vickie making cat ears with her hands in front of a cat-themed poster


On our way to find our dinner spot, we strolled through Vondelpark which is one of the largest parks in the city.

As the weather was great (basically every day while we were there) there were tons of people out. It was a lovely change of pace from walking through the city streets.


For dinner, we went to FoodHallen which I can only describe as a shopping mall food court cranked up to 11. There are several restaurants inside with many different cuisines and was very crowded.

We had the Dutch specialty Bitterballen, of course!

Closing Thoughts

This trip was incredible for me!

Amsterdam is a wonderful city, much greener than many cities here in the US. The many flowers and trees all along the canals were quite beautiful.

Getting to attend a conference on a topic that I’m quite passionate about and meeting wonderful folks that share that same passion was wonderful.

I honestly never thought I would get to meet some of the folks I have become friends with over the past couple of years in person, but I was overjoyed at the opportunity.

I learned so much and have already begun digging into some of the topics further to get a better understanding, expect more blog posts on some of the things I’m learning about.

Thank you to PPK, Krijn Hoetmer, and everyone else who helped make CSS Day an amazing experience!

I think I am going to try and make this event a yearly occurrence!

Let's work together!