What happens when you put developers, standards, and sushi in one room

Photos of the TPAC 2025 Hackathon

Last month at TPAC in Kobe, we hosted the W3C Hackathon: TPAC 2025 – Kobe Edition, and once again I was reminded why I love this community so much.

This was our second hackathon in this format, following last year’s event in Anaheim. Same spirit, new city, fresh projects.

We gathered in one of the rooms at the International Conference Center in Kobe, grabbed some sushi, and turned a Tuesday evening into three hours of focused chaos. The event attracted nearly 30 people, ranging from developers to spec editors to W3C staff. For some, it was their first hackathon ever.

Two tiny challenges for big impact

Participants had the opportunity to take on one of two challenges – both intentionally small in scope, so people could actually finish something in 90 minutes. Short for a hackathon? Definitely. But short on purpose: it encouraged quick thinking, tiny scopes, and decisive choices. No time to over-engineer, and just enough time to experiment.

Challenge #1: CSS Playground – Create a wild CSS demo. Anything that showed off the power (and weirdness) of CSS was fair game. HTML and JavaScript were allowed. AI tools were allowed too – as long as people could explain their process.

Challenge #2: Dashboard – Build a small dashboard or visualization. This could be related to W3C, the Web, or anything participants cared about. It could be just a concept or a working prototype – the focus was on insight and storytelling, not feature completeness.

Both tracks were eligible for LEGO prizes and had multiple placements. The constraints were simple: 90 minutes to build or sketch, work solo or in a pair, create everything during the event, and upload it all to a GitHub repo.

17 projects in 90 minutes

By the end of the night, participants had submitted 17 projects. Some were polished. Others were rough prototypes. All of them were genuinely interesting – and available to explore on the event website.