Schedule

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.

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.

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.

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

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.

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.

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.

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.

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.

What separates the top 1% of performers in tech from the rest? It’s not just talent or long hours – it’s how they think, lead, and operate daily. In this talk, I’ll break down the mindset shifts, micro-habits, and decision-making frameworks that set world-class engineers and leaders apart.Whether you’re an engineer aiming for staff level or a manager growing into executive leadership, you’ll learn:The 3 core philosophies top performers live by (with real-world examples)How to create leverage instead of just working harderWhy clarity beats hustle – and how to gain itHow to build your personal operating system for consistent growthThe surprising truth about confidence, visibility, and influenceBacked by coaching 100+ engineers and leading teams across LinkedIn, Netflix, and Salesforce, this session is packed with actionable insights for anyone ready to play at the next level.

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! 🚀

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.

Modern web development frameworks provide so many levels of abstraction that developers don’t need a deep understanding of the underlying runtimes or engines to hit the ground running. In fact, ease of use is the point of modern frameworks and a good indicator of their success. When spinning up an application, it’s easy to view Node as just “a piece of the puzzle,” and mistake it for a JavaScript engine, or a language, when, in reality, it is neither.It is valuable for developers to understand the differences between the engines and runtimes employed in their full-stack projects in order to have a mental model of how their code is being executed, and to optimize it for the environments in which it is running. The goal of this talk is to make clear the distinction between a JavaScript engine and runtime, to review how they interact with one another (in both servers and on the web), and to look at practical applications of this knowledge.

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.

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.

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?

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

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.

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.

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.

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! 🚀

Creating backend web framework with Web Standards APIsUsing URLPatterns for routingExpress/Hono-like syntaxContext/Middleware mechanismServer-side rendering with ReactFile-based routingWriting testsHow to take the benchmarksThis is reinventing the wheel, but making your framework is fun!

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.

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.

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.

The tech lead role is one of the most misunderstood and overlooked positions in the tech industry. Developers are promoted for their coding skills, yet success in this role is measured by leadership, not just technical ability. This shift can be disorienting because being a tech lead isn’t just about technology, it’s about people.Drawing from my experience as a tech lead at ThoughtWorks and coaching over 300 tech leads, I’ll explore why this role is uniquely complex. Positioned at the intersection of people, technology, and business, tech leads must develop critical soft skills like delegation, conflict resolution, and team alignment, yet most are thrown into the role without support.In this session, we’ll uncover why most tech problems are actually people problems and how to address them.