WebStorm IDE is researching developer experience flow state. We found that developers feel it is not productive alt-tabbing between IDE/ AI Agents, Figma and browsers trying to spot if everything matches. It’s a manual process that doesn’t scale when we are getting faster with AI. It's too late if these visual bugs hit a PR review, you've already lost the context needed to fix them without taxing your head space.

Is it possible or even desired to pull this validation directly into the development loop?
We'd like to show you our prototype on how we would like to combine the Figma Plugin APIs, WebStorm and Vitest Browser Mode to automate these checks while you code.

In this talk, we’ll explore the performance limits of SVG when rendering scatter charts with thousands of data points, based on our experience at MUI X Charts. You’ll learn how to identify bottlenecks, performance measuring tricks, and the techniques we use to optimize rendering.

In this talk, we'll dive into Client-Side Semantic Caching. I'll show you how to intercept user prompts in the browser, run a tiny open-source AI model locally to understand the "meaning" of the text, and serve previously cached answers instantly. We will look at real code using Transformers.js and IndexedDB to drop your AI latency to 0ms, save API tokens, and build a greener web

Modern JavaScript applications often pass automated accessibility checks with flying colors. Tools like Lighthouse, Axe, and CI pipelines give us green reports, and we feel confident shipping.

But what happens when real users interact with the application?
In this talk, we’ll explore why automated accessibility testing only catches a fraction of real issues. Through a live demo of a seemingly “accessible” JavaScript form (we will see on the Lighthouse and Axe DevTool no accessibility issues), we’ll uncover hidden problems that automated tools completely miss, such as broken keyboard navigation, silent dynamic UI updates, and modal dialogs that behave correctly visually but fail real users.

You’ll learn why accessibility is not just about passing automated checks, but about understanding how people actually interact with your JavaScript applications.

This session will include a live demo, practical examples, and concrete takeaways developers can apply immediately.

Devalue is the client-server serialization library used by SvelteKit. In this talk, I will go over why we want serialization libraries, the what and why of devalue, and the current limitations of devalue and other solutions.

Undo/Redo for geospatial drawing

[Free] and Open Source 4 Geo in the age of agentic work

Cognitive stress has always been a challenge when dealing with new languages, features and APIs. Oftentimes, we find ourselves experimenting with new features, rather than only reading their documentation. Either with a debugger, a REPL environment, or a thousand console.logs, we explore what these tools do. But what if there was something that will further cut the time between writing code and seeing the result? JS Eval is a tool that achieves exactly this by displaying the evaluation results of your program directly where they come from. Join me as we dive into its plethora of features and how they can help you understand the new tools you encounter!

A practical talk on we handled a concurrency use-case in a React application that we had (auth token refresh / duplicate requests) and how we made it using the library async-mutex coupled with RTK query.

How to instrument a React app for observability (traces, performance insights, debugging user flows), common pitfalls, and practical implementation tips.

An introductory presentation exploring the 5 Ws (Who, What, When, Where, Why) of GraphQL to understand if you should be using it as your daily API schema.