Videos of Design Systems Week 2025

How can cities make their design systems more transparent, consistent, and easy to use for developers? The City of Vienna found an answer in the Custom Elements Manifest (CEM) — a file format that describes custom elements and makes web components easier to document and use in code editors.

In this session, Manuel Matuzović shows how Vienna applies CEM to document and maintain its pattern library. He demonstrates how this approach improves usability, accessibility, and collaboration across teams.

TEDI is the design system for the Estonian public sector. What started two years ago as an internal tool quickly grew into a system used nationwide. TEDI replaced the previous design system VEERA from 2018, which didn’t offer components for developers. In this session, the TEDI core team shares their experiences: the successes and the challenges. They show how the system is technically structured, how the team works together, and how the design library has developed.

The Helsinki Design System is an award-winning open-source project, built to be accessible to everyone and available in English. This session delves into what it takes to document and scale a design system in practice—covering the real challenges of managing documentation workflows, and how to keep collaboration and consistency on track when the latest tools aren’t available. Gain insight into why process and mindset matter far more than tools, and how thoughtful documentation can make or break a design system.

Since 2020, extensive work has been done in Luxembourg on three testing methods for accessibility: web, mobile and PDF. These practical tests make it easier to check how a website or web application meets the European Standard (EN 301 549) for digital accessibility. These tests are useful for anyone working with WCAG and are now being used both in Luxembourg and internationally as an approach for accessibility audits. Alain will show how these testing methods work in practice. He will highlight the key benefits and explain how you can use and contribute to this Open Source initiative.