How Firefox renders web components
How Firefox turns a custom element into pixels, traced through Gecko's own source, from the registry to the reactions stack to the flattened tree Stylo styles.
Front-end & design systems studio
Let's build something great together.
Allons-y Studio builds the design systems & front-end foundations behind consistent, accessible products, so your teams ship faster with less rework & less risk.
Built with teams at Google, Adobe, & Red Hat
About the studio
Front-end friction becomes a system your teams ship on with confidence.
If your product experience is inconsistent, your handoff is brittle, or your front-end foundation is slowing delivery, Allons-y turns that friction into a scalable system: clear standards, accessible components, & a codebase your team can build on.
Founded by Cassondra, a front-end architect with deep experience in web components and design systems, Allons-y helps organizations, big or small, scale their work without trading speed for accessibility.
Services
Where the studio helps
Design systems architecture
Design systems built and scaled as product infrastructure, not just component libraries. That includes architecture, governance, accessibility, performance guardrails, and implementation patterns that help teams ship consistent UI faster across products.
Front-end engineering
Senior front-end consulting for audits, modernization, migrations, and complex implementation. Delivery risk drops as architecture, code quality, and accessibility improve on durable foundations.
Training & workshops
Practical training for engineering, design, and product teams, covering design systems, accessible front-end development, and team workflows, tailored to your roadmap. Your teams keep shipping the system long after the engagement ends.
New guide
How Firefox renders web components
Specs say what should happen; this is what Firefox actually does. Follow a custom element through Gecko's source & step through each stage as an interactive figure.
Read the guide“A walking encyclopedia on CSS, HTML, design systems, & accessibility. One of the best Design Engineers in the business.”
Writing
From the blog
From castastrophe.blog
Building something for the web? Let's talk.
Share your project & goals, and Allons-y Studio will reply with a way forward.