Name: JSNation 2025
Start: 2025-06-12T11:00:00.000Z
End: 2025-06-16T19:00:00.000Z

At VoidZero, we have been hard at work on building the foundation for a unified toolchain for JavaScript. Over the past year and half, we have reworked everything inside Vite from the ground up, now running on a Rust-powered toolchain containing OXC and Rolldown. In this talk, we will discuss the why, the implications, and the future vision of all this work.

Vite and the Future of JavaScript Tooling

Evan You

In modern apps we have millions of lines of code with data coming from a variety of data sources. To achieve swift user experience using a suspense-like pattern is non-negotiable. Only if there's something that could manage the complexities in suspense with prefetching, waterfalls, data dependencies, etc. How can we make suspense more resourceful?In this talk we'll see how templating and signals make the suspense pattern a breeze in Angular. Suspend your disbelief! There's a simpler async state with resources.

Resourceful Suspense

Minko Gechev

What if you could use multimodal LLMs to interact with websites or IoT devices using motion control?As advancements in multimodal AI offer new opportunities to push the boundaries of what can be done with this technology, I started wondering how it could be leveraged from the perspective of human-computer interaction.In this talk, I will take you through my research experimenting with building motion-controlled prototypes using LLMs in JavaScript.

Motion Control With Multimodal LLMs

Charlie Gerard

Node.js continues to thrive despite claims of its decline. We'll debunk myths, highlight recent enhancements, and demonstrate its robust performance in today's tech landscape. The talk will cover Node.js's role in server-side programming and cloud-native applications, community contributions, integration of modern JavaScript features, and influence of emerging technologies. We'll conclude by projecting Node.js's bright future and growth areas in the evolving tech world.

The State of Node.js 2025

Matteo Collina

A behind-the-scenes look at running the "State of" series of developer surveys (State of JS, CSS, etc.) as well as lessons learned and upcoming trends.

The State of the Web

Sacha Greif

Learn about Transformers.js, an innovative JavaScript library for running state-of-the-art machine learning models 100% locally in your browser. With support for nearly 2 000 pretrained models, spanning a wide range of modalities and tasks, Transformers.js empowers developers to seamlessly integrate advanced ML capabilities into their web applications. We'll also explore how we leverage emerging web technologies like WebGPU and WebNN to create interactive, privacy-preserving, and scalable web experiences.

Transformers.js: State-of-the-Art Machine Learning for the Web

 Joshua Lochner

Do you want to automate daily manual tasks or explore extending browser functionality? This talk has you covered; we’ll break down how to build Web Extensions from scratch – covering architecture, state management, Manifest V3, best practices and tools to bring your ideas to life! 🚀

Building Web Extensions With Your Favourite Framework

Alba Silvente Fuentes

In this talk, Thomas Steiner from Google Chrome's AI team dives into the various built-in AI APIs that the team is currently exploring. First, there's the exploratory Prompt API that allows for free-form interactions with the Gemini Nano model. Second, there are the different task APIs that are fine-tuned to work well for a particular task like translations, language detection, summarization, and writing or rewriting. After introducing the APIs, the final part of the talk focuses on demos, applications, and use cases unlocked through these APIs.

AI Right in the Browser With Chrome’s Built-in AI APIs

Thomas Steiner

AI progress is running away on the server-side, where the GPUs live, but the web platform is never that far behind. In this talk we're going to explore the incredible applications you can build in the browser today and in the near future.You'll see how to build an offline-capable, speech to speech language translation app, a babelfish, using nothing but the web platform. Through this app we'll explore the different ways we can run AI models in the browser today and what may be built into the browser in the future. From low-level standards to high-level experiments, you'll learn how to work with AI on the web.

The Built-in Browser-Based Babelfish

Phil Nash

In this workshop I’ll cover a repeatable process on how to spin up full stack apps in Cursor.  Expect to understand techniques such as using GPT to create product requirements, database schemas, roadmaps and using those in notes to generate checklists to guide app development.  We will dive further in on how to fix hallucinations/ errors that occur, useful prompts to make your app look and feel modern, approaches to get every layer wired up and more!  By the end expect to be able to run your own AI generated full stack app on your machine!

Building Full Stack Apps With Cursor Composer

Mike Mikula

Chrome DevTools just got a turbo boost! The Chrome DevTools team has been releasing new features at a furious rate over the past year, including  a complete Performance Panel overhaul with real-time Live Metrics and AI-powered Insights that'll expose bottlenecks you never knew existed. Forget tedious documentation searches and forum hunts; now, AI assists you directly within the Elements, Performance, Network and Sources panels, keeping you in the flow. Use the new alignment and collaboration tools to easily share your observations and debugging wizardry with your team and stakeholders, We'll unleash the full potential of these game-changing features, revealing hidden gems and shortcuts that'll transform your debugging workflow from a slog to a supercharged sprint. Get ready to code faster, debug smarter, and build experiences that fly.

Supercharge Your Debugging With the New Features in Chrome Devtools

Barry Pollard

Ewa Gasperowicz

In this workshop we'll dive into the latest advancements in React and best practices for building modern React apps. We'll take a look at modern NextJS and React Router 7 Framework (aka Remix) along with React's new "React Server Components". We'll also talk about improving the data-fetching strategies of your SPAs along with options for migrating your SPA to modern React Router.

Modern React Architecture

Brad Westfall

Get hands-on in this workshop where we'll create a GitHub Copilot Extension from scratch.We'll use the Copilot Extensions SDK, https://github.com/copilot-extensions/preview-sdk.js, and Hono.js, covering best practices like payload validation and progress notifications and error handling.We'll also go through how to set up a dev environment for debugging, including port forwarding to expose your extension during development as well as the Node.js debugger.By the end, we'll have a working Copilot extension that the audience can try out live.

Let's Create a GitHub Copilot Extension!

Nick Taylor

Let’s dive into the world of testing with Deno’s built-in test runner! Come on in, the water’s lovely!We’ll kick things off by exploring the principles of effective testing, perfect for beginners dipping their toes in. Then, we’ll introduce Deno’s out-of-the-box test runner.With the Deno.test API, you’ll be jetting in no time. We’ll cover how to write assertions and see firsthand how they help ensure your code behaves as expected.To wrap things up, we’ll explore writing tests that will be familiar to those experienced with Jest and Vitest, using Deno and its standard library. You’ll gain practical knowledge on how simple Deno makes setting up your testing environment, structuring your test cases, and optimizing your testing workflow.Whether you’re a seasoned developer or new to Deno, this talk will provide the tools and knowledge you need to confidently navigate the waters of testing in your Deno projects and make a splash with your testing skills!

Testing the Waters With Deno

Jo Franchetti

pnpm v10 added support for a new type of dependency called "Configurational dependencies". These dependencies make it possible to develop pnpm plugins and share your configurations between projects.

Configurational Dependencies in pnpm

Zoltan Kochan

Discover how you can shape the future of the web by contributing to web standards! In this talk, we’ll explore the process of creating and evolving web technologies, the role of standards organizations, and how developers of all levels can get involved. Learn practical steps to contribute your ideas, collaborate with global communities, and ensure the web remains open, accessible, and innovative for everyone.

Contributing to Web Standards

Hemanth HM

The European Accessibility Act (EAA) is coming, and companies will rush to certify their websites as accessible in the easiest way possible. But high Lighthouse and Axe scores don't mean real accessibility. Many will rely on these tools to "prove" compliance, despite their critical blind spots – broken focus, misleading ARIA, and inaccessible dynamic content. Even more confusing, Lighthouse and Axe are built on the same foundation, yet they can produce different results. So let's break down these flaws and explore better ways to ensure true accessibility.

a11y Testing Is Broken: How Lighthouse and Axe Fail in Real Projects

Glafira Zhur

Imagine the convenience of executing TypeScript files directly with Node.js using `node file.ts`. Just a few years ago, this concept seemed like a distant dream. Today, it stands as an exciting experimental feature. This talk narrates the journey of transforming this dream into a reality.

Run TypeScript Natively in Node.js

Marco Ippolito

Learn how Vite's Hot Module Replacement (HMR) works under the hood and all the key concepts that power it.

Hot Module Replacement is Easy

Bjorn Lu

IPFS is a peer-to-peer network distributing for content addressed data and can be thought of as a distributed CDN. Yet, given its evolutionary trajectory IPFS is often misunderstood. In this talk, you’ll learn about current state of IPFS with a focus on integration with the web platform using HTTP(S), how it enables local-first distribution of web apps, and real applications for you as a web developer.

Demystifying IPFS: A Web Developer's Guide to Content Distribution

Daniel Norman

Have we been stuck in the same testing pain loops for years? Even though it might seem like it, we haven't!Even if AI is now writing our tests, many JavaScript developers have faced numerous challenges, from the unclarity of test classifications to the struggle of mocking, long-running integration tests, and shifting everything to E2E tests.Let's recap everything that has happened in the past years and look into the present to explore what 2025 will bring for testing in the JavaScript world around test runners, testing libraries, mocking, production practices, and AI-based tools.

The 2025 State of JavaScript Testing

Daniel Afonso

Svelte 5 introduced runes which use signals under the hood. While signals are very cool and unlock a ton of composability possibilities they have their own gotchas... let's explore them while creating a reactive signal based system from scratch to really understand them from the base!

Surprise! Svelte Secretly Sending Signals

Paolo Ricciuti

Node has served you well: you spun up a prototype and iterated quickly, keeping up with the evolving requirements of a successful product. Nonetheless, as time goes on, cracks are starting to show up: an endpoint is slower than it needs to be, a data processing job that took seconds now takes almost an hour, and your infrastructure bill is growing too fast compared to the size of your user base. Engineers are starting to whisper: is it time for a rewrite? Should we pause feature development to rebuild everything on more solid foundations? That's an option, but it's expensive.There's another path: rather than throwing away your entire Node codebase to start over, you analyze your application and isolate the performance-critical bits—the so-called "hot modules" where your application spends most of its time. You will rewrite those in Rust and package them as a Node native extension. This talks shows you how.

Speeding Up Your Node Sever With Rust

Marco Otte-Witte

In TypeScript’s type system is more than just a tool for catching errors—it’s a way to solve complex problems with clean and reliable code. In this talk, we’ll dive into advanced TypeScript techniques like mapped types, conditional types, and generics to handle even the trickiest type challenges.You’ll see how these techniques can help you extract, transform, and validate data types while keeping your code simple and maintainable. These "TypeScript gymnastics" aren’t just for show—they’re practical skills that make your systems stronger and easier to work with.Come learn how to take full advantage of TypeScript’s flexibility and power to build solutions that are as smart as they are safe.

TypeScript Gymnastics: Why Are They So Powerful for You?

Luca Del Puppo

Modern web applications need to be responsive and smooth, providing users with immediate feedback for their interactions. To understand how well our applications perform, we need to understand how browsers process and render content. This is why we now have AnimationFrames, a new representation of unit of work that powers INP and LoAF APIs!

What Is an AnimationFrame and What Can It Tell You?

Vinicius Dallacqua

Modern JavaScript bundlers are architectural marvels that transform complex codebases into optimized production assets. This technical deep dive deconstructs how bundlers like Vite, webpack, or Rollup work under the hood, revealing the engineering that powers our build tools. We will journey through the bundling pipeline, starting from the understanding of the AST, parsing and static analysis for dependency resolution, some core optimizations like tree-shaking and code spitting, closing with some advanced concepts like HMR.

Bundlers: A Deep Dive into Modern JavaScript Build Tools

Edoardo Dusi

The story behind the project, its mission to curate the best of the JavaScript ecosystem, and how it has adapted to the ever-changing landscape. We’ll also explore the key trends, tools, and technologies that have shaped JavaScript over the past decade.

10 Years of Best of JS

Michael Rambeau

Signals have been revolutionizing state management lately, offering a more intuitive and performant approach than traditional methods. But what kind of magic is there under the hood? You change a value, and all places that use that value update and recalculate themselves automagically… 🤔In this talk we will look behind the curtain and explore the inner workings of Signals, by building our own implementation from scratch (Disclaimer: use for learning purposes only 😉).Signals have become almost a de facto building block in JavaScript frameworks lately, with some notable exceptions (looking at you React 👀), so it really pays off to have a deeper understanding about how they operate, how to debug them effectively and how to avoid common pitfalls. Plus, who doesn't like a bit of live coding? ✨

Build Your Own Reactivity: A Deep Dive Into Signals

Carl Vuorinen

This is the story of how I almost spent a night on the street — because of JavaScript's Date object! We'll dive in and try to understand why that happened, and how to prevent it. Luckily coming soon to a browser near you is Temporal, the JavaScript built-in API that makes this kind of mess-up a thing of the past.

Temporal: The Curious Incident of the Wrong Nighttime

 Philip Chimento

Dive into the environmental impact of the web through key insights from the HTTP Archive Almanac 2024. Discover shocking statistics about web sustainability, from massive page weights to unused code, and learn practical, immediate solutions to reduce your website's carbon footprint. This talk combines hard data with actionable strategies to make the web greener

Web Almanac 2024: Is the Web Sustainable? 

Burak Güneli

JSR is a community-driven, modern JavaScript registry with a mission to improve the ecosystem through transparency, openness, and innovation. Hear about recent developments, including the establishment of its governance board, ongoing projects and initiatives, and how these efforts directly benefit JavaScript developers. Discover how the community can engage directly, contribute to JSR’s direction, and get insights into the project’s goals and upcoming milestones.

JSR: Building an Open Registry for the JavaScript Community

Leo Kettmeir

Ever used an app that crashed and thought, "Why can’t this just work?" For users, it’s frustrating. For businesses, it’s expensive. As JavaScript developers, we’re stuck in the middle - juggling frontend tweaks, backend performance, and monitoring tools to figure out what went wrong. That’s where observability comes in because understanding your code is like going to the gym. No shortcuts, no pills. You gotta put in the work to put on the muscle.  It’s not just some SRE buzzword anymore but a must-have for developers. Observability helps you spot issues, understand system behavior, and fix problems faster. And with OpenTelemetry, you get an open-source framework to manage logs, traces, and metrics without vendor lock-in. In this session, you’ll learn, all things observability, optimize both frontend and backend, and integrate OpenTelemetry to gain insights into your system. Moreover, you'll also learn how to practically integrate OpenTelemetry into your JavaScript apps, to create spans, track activities, name them effectively. The result? Fewer headaches, better performance, and apps that not just works but you completely understands.

When JavaScript Meets OpenTelemetry: It's Observability O'Clock

Yash Verma

In this session, we’ll explore why JavaScript’s single-threaded model causes UI lag, why setTimeout() and requestIdleCallback() fail at task prioritization, and how scheduler.postTask() finally gives developers fine-grained control over execution.Through real-world examples, performance analysis, and a live demo, we’ll show how prioritized scheduling can eliminate UI freezes, improve responsiveness, and make JavaScript execution truly user-centric. If you care about JavaScript performance, this is the talk you don’t want to miss! 🚀

JavaScript Isn’t Slow – It’s Just Scheduled Wrong

Sulagna Ghosh

Starting a new application? Have an existing application that is growing? Choosing the right authentication solution can make or break your product. Should you buy a solution, build your own from scratch, or try an open-source project? The pros and cons of each approach will be discussed. Whether you are a startup founder, product manager or developer, this session will equip you with the insights needed to make an informed choice that aligns with your business goals and technical requirements.

Auth: Build vs Open Source vs Buy

Mark Robustelli

Explore a world of hardware the likes of which you've never seen before! This presentation will contain live demos using both local robots and those in production from across the country. While the technology being used is advanced, the approach is accessible to anyone whose used JavaScript before.The talk covers the architecture of WebRTC as a stack of technologies for enabling peer-to-peer communication, as well as how it can be leveraged for interacting with embedded hardware and robotics from the browser, all using JavaScript APIs. My goal is to make programming devices more accessible to web developers and demonstrate a practical solution for taking hobby projects from your desk to production.

Real-Time Robot Control From the Browser With WebRTC

Nick Hehr

In October 2024, a language evolution proposal was submitted to the TC39 Javascript Committee meeting. In it, a new vision for JS as a whole is shown, one in which the language is seemingly split in two - a core ""JS0"" and an extended ""JSSugar"". What is this about, why did it come up at this point and what does it mean for us as JavaScript developers?In this short talk, we'll go over the proposal, exploring what it tries to accomplish, how and its potential pros and cons from a neutral, community-first perspective.

Divide and Conquer? - Exploring the 'JS0' and 'JSSugar' Proposal for JavaScript Evolution

Daniel Hervás

As IT professionals, we play a critical role in energy consumption and emissions, and it's our responsibility to address this impact. By adopting greener practices in web development, we can contribute to achieving climate goals while still driving innovation and growth. I'll share insights of how we integrated principles of green web development in the redesign of our website and explain their impacts.

Sustainable Web Development in Startups: Applying Green Coding Principles for a Greener Future

Katharina Fetzer

As third-party script developers, we constantly work in environments we don't fully control. We must handle unexpected issues introduced by different browsers, quirky customizations made by the primary developer team, and security restrictions we can't easily bypass. In this introductory-level session, I will share first-hand experiences and practical guidance derived from building and deploying third-party scripts to improve your team's confidence and workflow efficiency.

Third-Party Scripts: Surviving the Wild West of the Web

Anton Zalaldinov

In this workshop, we’ll explore how to manage application configurations directly in your Git repository and integrate them into the TypeScript type system. The goal is to make your code aware of the actual configuration at compile-time, reducing the need for runtime validation and unit tests.You'll discover:<ul><li>How to create lossless types for static data</li><li>Techniques to eliminate unnecessary code paths and reduce runtime validation</li><li>How to leverage utility types to extract specific information from configurations</li><li>Key TypeScript operators and how to handle common pitfalls when working with generic types</li><li>Best practices for improving type safety and developer experience</li></ul>By the end of this workshop, you'll have a solid understanding of how to implement Config as Code in your TypeScript projects, enhancing maintainability, type safety, and autocomplete support. This workshop is ideal for TypeScript developers looking to optimize their code and streamline configuration management.

Live Coding: Eliminating Redundant Runtime Checks with Config as Code&Type in TypeScript

Jannik Sommerfeld

A centralized prompt engineering toolkit to help developers build better applications powered by LLMs. This toolkit provides tools and best practices for crafting effective prompts, managing prompt versions, and evaluating the performance of LLM-based features. Furthermore, there’s a need for version control, collaboration, and robust safety measures (hallucination checks, standardized evaluation framework, and a safety policy) to ensure responsible AI usage.

Prompt Engineering Toolkit

Manoj Sureddi

Remember when Flash ruled the web, and you could build mind-bending interactive experiences without battling WebGL shaders, fighting scene graph hierarchies, or summoning dark forces to debug matrix transformations? Good times.   Now, 3D web development is back—with WebXR, Three.js, and WebGPU leading the charge—but where’s the tooling to match? In this talk, we’ll explore how modern devs can reclaim the golden age of interactive 3D without losing their sanity, diving into the pain points of today’s workflows and the solutions that are making immersive development fun again.

How We Rebuild the Creative Playground That Flash Took to the Grave

Connell Gauld

JavaScript is evolving beyond web development and into the realm of high-performance numerical computing. In this talk, we’ll explore the current landscape of scientific computing in JavaScript, compare its performance with Python and C, and discuss what’s missing. Through live demos – including AI, real-time data processing, and mathematical computing – we’ll see how libraries like stdlib and a few others are shaping the future.

The Future of Numerical Computing in JavaScript

Gunj Joshi

The way we write code is fundamentally changing. Instead of getting stuck in nested loops and implementation details, imagine focusing purely on architecture and creative problem-solving while your AI pair programmer handles the execution. In this hands-on workshop, I'll show you how to leverage Cline (an autonomous coding agent that recently hit 1M VS Code downloads) to dramatically accelerate your development workflow through a practice we call "vibe coding" - where humans focus on high-level thinking and AI handles the implementation.You'll discover:<ul><li>The fundamental principles of "vibe coding" and how it differs from traditional development</li><li>How to architect solutions at a high level and have AI implement them accurately</li><li>Live demo: Building a production-grade caching system in Go that saved us $500/week</li><li>Techniques for using AI to understand complex codebases in minutes instead of hours</li><li>Best practices for prompting AI agents to get exactly the code you want</li><li>Common pitfalls to avoid when working with AI coding assistants</li><li>Strategies for using AI to accelerate learning and reduce dependency on senior engineers</li><li>How to effectively combine human creativity with AI implementation capabilities</li></ul>Whether you're a junior developer looking to accelerate your learning or a senior engineer wanting to optimize your workflow, you'll leave this workshop with practical experience in AI-assisted development that you can immediately apply to your projects. Through live coding demos and hands-on exercises, you'll learn how to leverage Cline to write better code faster while focusing on what matters - solving real problems.

How to 10x Your Development Speed with Cline

Nik Pash

Join me as we take a look into the dark side of micro-frontends - dependency duplication. Ever wondered what happens to your overall bundle size when you break a huge SPA into dozens of micro-frontends? In this session we’ll share our journey with sharing dependencies between micro-frontends in monday.com to reduce overall bundle size on the page and increase performance.

Sharing Is Caring – Boosting Micro-frontends Performance With Dependency Sharing

Sahar Brodbeker

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Discover the future of the JavaScript development ecosystem and get connected to its stellar crowd! 

JSNation is the best place to learn about JavaScript – beside the main JS conf talks and panel discussion with high-profile specialists, be prepared for awesome MCs, in-depth workshops, a number of discussions & networking rooms, interactive entertainment, and engaging challenges for all participants.

JSNation 2025

FocusReactive

Tiny

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Sentry

Twilio

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Datadog

CodeRabbit

Typesense​

Datadog is a SaaS-based monitoring and security platform for infrastructure, applications, logs, and more. Through its fully unified platform, Datadog delivers complete visibility into the performance of modern applications. <a href="https://www.datadoghq.com/" target="_blank" rel="noopener noreferrer">More details.</a>

Sentry helps every developer detect, understand, and fix broken code, fast. Using Sentry’s debugging platform–that favors action over dashboards–decreases resolution time from days to minutes, resulting in freed up dev cycles and happier customers. <a href="https://sentry.io/welcome/" target="_blank" rel="noopener noreferrer">More details</a>.

Sentry is essential for monitoring application code quality. From Error tracking to Performance monitoring, developers can see clearer, solve quicker, and learn continuously about their applications — from frontend to backend.&nbsp;

Twilio is a Cloud Communications Platform for developers. If you would like to send an SMS, program a phone call or send a Whatsapp message; you can do all of that and more with Twilio. <a href="https://www.twilio.com/try-twilio" target="_blank" rel="noopener noreferrer">More details</a>.

Twilio is a Cloud Communications Platform for developers. If you would like to send an SMS, program a phone call or send a Whatsapp message; you can do all of that and more with Twilio.

Get RCS on Twilio Messaging — no code changes required

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CodeRabbit is an AI Code Reviewer that works with your existing tool chain like ESLint, Biome, and provides context-aware code review comments with 1-click computable suggestions.&nbsp;CodeRabbit is free for open source.&nbsp;

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JSNation 2025

The main JavaScript conference of the year