#react

A behind the scenes look at the design and development of the all-new React docs at react.dev. The new react.dev launched this year introducing new methodologies like challenges and interactive sandboxes and subtle inclusivity features, like "international tone" and culturally agnostic examples. Not only have the new docs changed how people learn React, they've inspired how we think about developer education as a community. In this talk, you will learn how the React team and some ambitious community members made the "React docs rock" for a generation of front end developers and how these new patterns and established techniques can be applied in your favorite projects.

Next.js and other wrapping React frameworks provide great power in building larger applications. But with great power comes great performance responsibility - and if you don’t pay attention, it’s easy to add multiple seconds of loading penalty on all of your pages. Eek! Let’s walk through a case study of how a few hours of performance debugging improved both load and parse times for the Centered app by several hundred percent each. We’ll learn not just why those performance problems happen, but how to diagnose and fix them. Hooray, performance! ⚡️

React provides a contract to developers- uphold certain rules, and React can efficiently and correctly update the UI. In this talk we'll explore these rules in depth, understanding the reasoning behind them and how they unlock new directions such as automatic memoization. 

Server components, introduced in React v18 end these shortcomings, enabling rendering React components fully on the server, into an intermediate abstraction format without needing to add to the JavaScript bundle. This talk aims to cover the following points:1. A fun story of how we needed CSR and how SSR started to take its place2. What are server components and what benefits did they bring like 0 javascript bundle size3. Demo of a simple app using client-side rendering, SSR, and server components and analyzing the performance gains and understanding when to use what4. My take on how rendering UI will change with this approach

React 18! Concurrent features! You might’ve already tried the new APIs like useTransition, or you might’ve just heard of them. But do you know how React 18 achieves the performance wins it brings with itself? In this talk, let’s peek under the hood of React 18’s performance features: - How React 18 lowers the time your page stays frozen (aka TBT) - What exactly happens in the main thread when you run useTransition() - What’s the catch with the improvements (there’s no free cake!), and why Vue.js and Preact straight refused to ship anything similar

In this talk, we'll look at some of the modern options for building a full-stack React and GraphQL app with strong conventions and how this can be of enormous benefit to you and your team. We'll focus specifically on RedwoodJS, a full stack React framework that is often called 'Ruby on Rails for React'.

Conditional rendering issues in JSX, forwardRef, serveral ways to create refs, render props (yeah they still exist), higher-order components (do they still exist?), act, non-extendable classes, SuspenseList (well, maybe in 10 years), React.FC and of course our good old friend useEffect. All these weird things are part of our favourite library (not a framework™) and yet we still use and love it. Why actually? Let's talk about. Disclaimer: This is not a very serious talk, mostly …

TypeScript and React are inseparable. What's the secret to their successful union? Quite a lot of surprisingly strange code. Learn why useRef always feels weird, how to wrangle generics in custom hooks, and how union types can transform your components.

React is a library for "rendering" UI from components, but many users find themselves confused about how React rendering actually works. What do terms like "rendering", "reconciliation", "Fibers", and "committing" actually mean? When do renders happen? How does Context affect rendering, and how do libraries like Redux cause updates? In this talk, we'll clear up the confusion and provide a solid foundation for understanding when, why, and how React renders. We'll look at: - What "rendering" actually is - How React queues renders and the standard rendering behavior - How keys and component types are used in rendering - Techniques for optimizing render performance - How context usage affects rendering behavior| - How external libraries tie into React rendering

Can useEffect affect your codebase negatively? From fetching data to fighting with imperative APIs, side effects are one of the biggest sources of frustration in web app development. And let’s be honest, putting everything in useEffect hooks doesn’t help much. In this talk, we'll demystify the useEffect hook and get a better understanding of when (and when not) to use it, as well as discover how declarative effects can make effect management more maintainable in even the most complex React apps.

Typically I talk a lot about deeply technical concepts like TypeScript, type systems, (im)mutability, MobX, Immer etc. But this time it's going to be personal and I'll share lessons, good and bad, about growing as an engineer. I've been leading open source projects, short lived projects as a freelancer and I went through the transition of engineer to tech lead twice. Both at a young startup and at Meta. This talk will be about personal experiences, unpopular opinions and even actions, and anything else that might be counterintuitive. Join for some take-aways for anyone aiming at an engineering focused career. Probably I will be wrong about most things, so don’t miss the opportunity to follow up afterwards!

Writing fluid user interfaces becomes more and more challenging as the application complexity increases. In this talk, we’ll explore how proper scheduling improves your app’s experience by diving into some of the concurrent React features, understanding their rationales, and how they work under the hood.

We've heard a lot about React's Fiber Architecture, but it feels like few of us understand it in depth (or have the time to). In this talk, Tejas will go over his best attempt at understanding Fiber (reviewed by other experts), and present it in an 'explain-like-I'm-five years old' way.

I want to provide an in-depth overview of the important concepts behind reconciliation. We'll then explore how React uses the algorithm and go through a few magic words we hear a lot, like coroutines, continuations, fibers, generators, algebraic effects and see how they all relate to React.js.

With concurrent mode coming in React 18, let's talk about the complexities behind providing declarative APIs for concurrent rendering. While implementing concurrent mode APIs from scratch for Brahmos.js, I came across lot of use cases and variability which made it one of the most interesting problem to solve, and appreciate more the React's effort on advocating Concurrent UI. In this talk we will see what concurrent mode means for a web app, what are the internal complexities and how I solved it for Brahmos.js.

React 18 introduces new APIs for rendering applications asynchronously on the server, enabling a simpler model for architecting and shipping user interfaces. When deployed on edge networking platforms like Cloudflare Workers, we can get dramatic performance and user experience improvements in our applications. In this talk, Sunil will demo and walk through this new model of writing React applications, with some insight into the implications for data fetching, styling, and overall direction of the React ecosystem.

If you’re building a dashboard, analytics platform, or any web app where you need to give your users insight into their data, you need beautiful, custom, interactive data visualizations in your React app. But building visualizations hand with a low-level library like D3 can be a huge headache, involving lots of wheel-reinventing. In this talk, we’ll see how data viz development can get so much easier thanks to tools like Plot, a high-level dataviz library for quick & easy charting, and Observable, a reactive dataviz prototyping environment, both from the creator of D3. Through live coding examples we’ll explore how React refs let us delegate DOM manipulation for our data visualizations, and how Observable’s embedding functionality lets us easily repurpose community-built visualizations for our own data & use cases. By the end of this talk we’ll know how to get a beautiful, customized, interactive data visualization into our apps with a fraction of the time & effort!

Documentation is often your community's first point of contact with your project and their daily companion at work. So why is documentation the last thing that gets done, and how can we do it better? This talk shares how important documentation is for React and React Native and how you can invest in or contribute to making your favourite project's docs to build a thriving community

Remix is a new web framework from the creators of React Router that helps you build better, faster websites through a solid understanding of web fundamentals. Remix takes care of the heavy lifting like server rendering, code splitting, prefetching, and navigation and leaves you with the fun part: building something awesome!

Have you ever wanted to break the rules and be a React troublemaker? I’ll show you how ignoring React’s best practices can improve performance, all without major rewrites to your codebase. To understand how, we’ll learn when React decides to render and how to trick it to render less frequently. We’ll build components that don’t render anything, conditionally call hooks, and even use a piece of Svelte - all to quickly fix real performance problems I encountered at Microsoft.

Join me on a musical journey through the world of open source software as I share the story behind crafting from scratch an online guitar tuner with Javascript.In this talk, we'll explore the delightful intersection of mathematics and development, where a simple curiosity led to the creation of an open-source tuner using React and Next.js.I'll share insights and challenges into the implementation of the tuner, navigating through the algorithmic landscape of autocorrelation and frequency calculations.

Building end-to-end encrypted applications is exciting, but also intimidating. This talk is designed to lower the entry barrier, offering a clear roadmap for integrating end-to-end encryption in collaborative, real-time applications.We begin by unveiling a simple design with one shared encryption key, promptly addressing its inherent challenges. Progressively, we delve into tools like Opaque, Secsync and CRDTs to tackle the challenges we identified and enhance our application with the goal of offering a seamless user experience without compromising on security.Each segment of the talk starts with an accessible overview before diving into practical, code-based examples. This approach not only demystifies the intimidating theory and empowers attendees with the tools and knowledge to apply these principles effectively in their projects.

No more loaders, no more errors - Suspense has revolutionized the way developers handle asynchronous operations.But have you ever wondered what magic enables Suspense to work? How does Suspense know it has to display a fallback because a query is going to happen in a component below?In this talk, we’ll explore the inner workings of Suspense to uncover the magic that empowers one of the most beloved components of React.

In this talk, I'll take you through my journey as I joined the team supporting our Smart TVs application and share my experience learning one of the most overlooked but essential pieces of functionality we have.

Is the Virtual DOM pure overhead? In this tech talk, Aiden Bai explores the performance implications of the Virtual DOM in frameworks like React and presents an alternative approach called the \"block virtual DOM.\" Aiden delves into the origins of the Virtual DOM, its purpose in addressing performance issues, and the process of diffing and reconciliation. The talk introduces the Block virtual DOM, which takes a different approach to diffing by using static analysis and dirty checking.

I wanted to have a tea menu to show guests and for my own reference. Turns out e-Readers use so little power and can render HTML! I'll share how to generate an e-book with all your drinks with React, JSX, and Deno, as well as rendering a custom cover page with SVG. Wow your friends by turning an old device into a smart home tea menu, and learn how to write your next book with React.

This talk focuses on building a production-grade consumer social application - https://guild.host . If you visit that site, would you be able to tell it's built using React Native just by looking and using it?

At a high level, Taz talks about what makes that possible and how the audience should consider application architecture.

At a lower level, Taz focuses on:
- How React's component composition model makes accommodating multiple platforms easy
- How large applications should use a Design System, and the Tamagui Design System comes with an optimizing compiler that outputs straight platform-specific code while the developer still writes high-level UI that happens to utilize React Native's components
- How to Server-Side Render a React Native Web application, and what considerations Guild made when choosing to create a custom SSR engine on top of Cloudflare Workers
- In order for Guild to exist anywhere, they need to embed themselves into other experiences. This involves Third-Party React Native on the Web and other platforms
- The future of this architecture, where Third-Party UI is the same as First-Party UI

In this talk, we will explore how Valtio can simplify your React state management by providing a minimalist and performant solution. We will cover the basics of Valtio, including how to create and update a store and how to access and modify the store from your components. We will also dive into some advanced Valtio features, such as subscribing to changes in the store, andusing memoization to optimize your components' performanc. By the end of this talk, you will have a solid understanding of how Valtio can make your state management more efficient and effective, allowing you to create scalable and maintainable applications.

React server components (RSCs) are a huge paradigm shift for React. You might even ask if NextJS and server components are the same thing (spoiler: they're not!) This talk demystifies how RSCs *really* work outside the framework. We'll build our own Node server, hook up the RSC renderer by hand, and understand the bundling and routing logic to ship a server component to your browser. Yes, all with live coding. What could go wrong...?

I wanted to have a tea menu to show guests and for my own reference. Turns out e-Readers use so little power and can render HTML! I'll share how to generate an e-book with all your drinks with React using Deno, as well as rendering a custom cover page with SVG. Wow your friends by turning an old device into a smart home tea menu, and learn how to write your next book with React.

Are you using React in your project? If so, you must used useEffect! Actually, it’s essential for many use cases, but there are instances where it might not be the best solution, and avoiding it can improve your application's performance.
In this talk, we will learn from experience which is the missing piece of the puzzle to master useEffect. Taking a look at the incorrect cases and trying to improve their performance helps us to have a deeper understanding of it.

UI’s are composed of fast parts, and slow parts in terms of how responsive they are to user interaction. React's concurrent renderer decouples the fast parts from the slow parts by allowing us to render the slow parts in the background without blocking the fast parts, so that each part can respond to user interaction at its own pace. In this talk, we'll explore Concurrent React, understand what problems it solves, how it works and how to leverage it through the use of concurrent features.

The prevalent advice on how to use React today is to use a framework: either to start with one or to incrementally adopt one. This deep-dive talk will explore why, and how to go about this with live code examples.

Our ecosystem can be overwhelming! First, we had the rise of SSR and SSG—and each had its own gigantic pile of frameworks and tools. Then partial hydration enabled us to hydrate only some of our components on the client, which we've seen in React Server Components. 
But what about islands? Do they relate at all to Streaming SSR? Moreover, what is resumability, and why do I keep hearing about it? […] Oh, did anyone say rendering on the Edge?
Well… There are many approaches out there, and all of them argue that their philosophy is best. In this session, we’ll go over these architecture/rendering patterns, to help shed some light on how some are implemented and the concepts behind them.

NextJS 13.4 changed the game with the App Router and React Server components. The change to the state management model looks simple to start, but gets complex very quickly as you try to create the practical every-day user experiences that were straightforward in the pages model. We'll talk about the different state management models, how they work in the App Router, and how to decide which you should use.

When working with React it is important that we use the right tool for the right job. If not we will be missing out on the best performance and developer experience. While optimising AG Grid React Table we discovered a number of patterns that made significant improvements to the tables performance.

For many app developers, GraphQL is instrumental in building great user experiences. With the introduction of React Suspense, developers have an ergonomic way to orchestrate loading states to improve upon the status quo. In this talk, the Apollo Client team will show you how we built a non-trivial application using Apollo Client’s new Suspense features, GraphQL features like the @defer directive, and how to combine them to build great user experiences in your own apps.

In this talk, I will share my experience in game development using ReactJS/CSS. We will explore how to make the most out of the component management provided by this library, along with the capabilities of CSS for creating an appealing user interface. Additionally, we will uncover how to leverage the React Three Fiber library to create games with a 3D experience.

In this talk, we will be going over a number of common useful and best-practice-proven TypeScript patterns to use in React 18. This includes how to correctly type component properties, children and return types, using React's built-in types, typing contexts, and the usual enum rant (but constructively).

Join me in a thought-provoking discussion on Bringing Controversial Ideas to React.js, where we will explore some of the most debated topics in the React ecosystem. This talk delves into the concepts of mutability and observability in React and compares them to frameworks like Solid.js and Svelte. We will also discuss the debate on granular updates versus Reconciler and the potential of a plugin system to extend React applications, and the impact it could have on the React community. Attendees will gain a deeper understanding of React's challenges and controversies compared to other frameworks and how the community is addressing them.

Machine learning is seen by many as the next step in artificial intelligence towards a new stage of human evolution. And thus helps us find new approaches to solving real-world problems. Phew... That sounds complex… And how is that supposed to be fun? Well, in addition to the big issues of our time, it is ultimately just another tool that we can play with. While it is important to first understand the core concepts of machine learning, we can quickly go way beyond that. Get ready for some unexpected examples of how to get started with machine learning in your React application!

In this talk, I'll explain React Query from a different perspective. After having maintained React Query for over two years and having answered many questions (often the same ones multiple times), I feel like there might be a fundamental understanding missing about the lib. I'll start with a quick introduction about my journey into open source and how I got to know React Query, followed by showing which mindset change is beneficial when working with React Query - how to "think in React Query". I'll have 3 major takeaways: 1) React Query is not a data fetching library It's an async state manager, we'll quickly talk about what makes a state manager, why React Query is one and what "async state" means. 2) staleTime is your best friend I've seen a bit of confusion about how to use React Query as a state manager, so I'll explain why setting staleTime is mostly all you need 3) parameters are dependencies This is important to understand to show the boundaries between client state and server state, and is essential when doing state management with React Query I will then end with a note on "separation of concerns" and about the tradeoffs of just calling `useQuery` wherever you need it in your component tree.

Have you ever questioned whether Javascript is a viable alternative to Python or R for creating machine learning models? After all, a 2019 survey by Stack Overflow found that Javascript is the language that developers use the most. Given that machine learning models like neural networks require a lot of computational power and that javascript was not intended for high-speed computing, this approach seems unreasonable. But hold on, this not entirely true, as javascript libraries like Onnx.js and Tensorflow.js are here to save the day! I'll be going into further detail on how to create intuitive and innovative machine learning applications with React in this talk.

In this session, I will discuss our experiences in overcoming performance limitations while developing React components for web apps on low-end embedded devices such as Smart TVs. I will share actual application cases from the development of millions of webOS Smart TVs and show how we improved user input response and app launch time. The ideas and techniques shared will be beneficial to developers facing similar challenges.

So CRA is no more and it probably was about time. The React docs suggest Next, Remix or Gatsby...but you're not ready yet for a full-blown React Meta-Framework and really just want pure React. Any alternatives? In this talk, I'm going to explore exactly that. We've got 7 minutes, so no slides, just code where we're going to set up a new React standalone application using Nx.

WASM has taken over the web-development scene in the past few years. It is a language that can be run by the web platform alongside with Javascript. Being treated as a target language, a variety of low-level, statically-typed languages such as C++ and Rust can be compiled to WASM. Thus, a variety of complex, computationally intense applications can now be tackled through readily available web applications. Demos of 2 such applications are shown in the presentation and a side-to-side comparison is done next to JS code.

Meta frameworks are increasingly popular. People dunk on React all the time. Are you insane for still using React? The talk is going to cover how real companies make this evaluation of which framework to choose. It's talking about the advantages of using React, primarily focusing on the positives but also offering constructive thoughts on why you might not want to.Should you use React in 2023?

It’s the hooks rule number one: “Only call hooks at the top level”.
But what if I told you that this rule does not apply to every hook? One of them can actually safely be used conditionally. 
To understand how useContext is different from other hooks, and why it is exempted from this major rule, we need to know why this rule exists in the first place. We will build our own mental model of react’s rendering behavior, focused on how react keeps track of data at runtime: props, states, refs… and context values.

An early look at using server components via Bun’s new bundler, with and without React.

This talk gives an introduction about MediaPipe which is an open source Machine Learning Solutions that allows running machine learning models on low powered devices and helps integrate the models with mobile applications. It gives these creative professionals a lot of dynamic tools and utilizes Machine learning in a really easy way to create powerful and intuitive applications without having much / no knowledge of machine learning beforehand. So we can see how MediaPipe can be integrated with React. Giving easy access to include machine learning use cases to build web applications with React.

Did you know that Chrome extensions, or web extensions, are written in plain HTML, CSS, and JavaScript? That means you can use React to write fully featured and sophisticated web extensions using the web development skills you already know. During this talk, we'll go over the basics of web extension development, how to set up a build process for an extension using React, and review a fully functioning extension that's in the Chrome web store right now!

What is a generic component? How to write them? When to use it?

Did you know that about 250 000 websites are published every day? The majority uses too heavy fonts, unnecessary images or utilises redundant libraries generating carbon footprint. ec0lint is a tool for frontend developers that mitigates the carbon footprint of websites by showing tips on how to create a more climate-friendly code. Thanks to code optimization ec0lint can help in reducing emissions from 1.8 g to ~0.2 g per one view saving 216 kg CO2 for each website (-88%!) annually.

We already know, ""if some task takes time, promisify it!"". But some tasks can be computation heavy and can take time to complete, so making them async is of no use since those have to be anyway get picked. Solution? Simple, multithreading! Yeah I know that React and in turn javascript is single-threaded but what if I told you that our life was a lie ever since? Enter web workers! Key takeaways of the talk: 1. An example of a simple product search showing why async js or concurrent mode cannot work. 2. Demystifying web workers. 3. How they make this magic happen under the hood? 4. The Question of life - Aren't they same as concurrent mode? 5. Comparing the same Product list app using web workers, diving deep into the performance. 6. How one can easily misuse web workers and how to avoid it.

There are amazing tools out there providing you with excellent type safety. But when you get to the client-side fetching, things go wild. Even if you have perfectly typed backed, you lose the type information during the client-side communication. Yes, you can use GraphQL or protobuf and generate types, but... what if I told you there's an easier way? A way that lets you develop your apps smoother than with REST or GraphQL? How? RPC! Say hi to maximum productivity with fantastic developer experience.

With React 18 the long awaited concurrent features are now available to the public. While they technically do not introduce new restrictions about how we build our components, there are many patterns that previously worked but might now introduce subtle bugs in your apps. Let's re-learn the rules of React so that we can stay safe in this new concurrent world.

Emerging build tools such as Bun, ESBuild, SWC and Rome will transform how we work with React in the future. Let's take a look at their current state, look at what's needed to adopt them and predict how the landscape will evolve.

How many times in your developer career you forget to remove an event listener? Close web socket connection? Unsubscribe from updates from any source? Or you are just to run some cleanup tasks, but every time you should do it manually. In this talk, I will show a new concept “Lifetime”, which will change your mindset about solving the problems above, make it all easy and even automated. I will show how I use it in everyday development and how it makes my application better and secure. I will also show how it improves DX and productivity. And I believe it’s something your team might want to use too.

What's React like if you come from a C#/C++ and Unity background? Making tools is easy, but can you ship a whole game with it?

Remix entered the stage with a unique and refreshing take on how to develop on the web. But how do you integrate it into your existing ecosystem of applications? Do you want to test-drive Remix on a small project, or do you want to go full-in, but it is tricky to do a big-bang migration from your existing React app? In this talk, we're going to explore how a monorepo-based code organization can help integrate Remix with your existing React and TypeScript infrastructure, facilitating high code reuse and a migration path to Remix.

The Great British Public Toilet Map is an open source, community driven project dedicated to helping people find toilets across the UK, with around 14,000 loos recorded and counting. In 2021 we took on the challenge of migrating the project from a SPA React app written in JavaScript to NextJS and Typescript. Together we'll discover why we decided it was time to migrate, the myriad technical challenges we faced along the way, how this work benefits our users, and the many exciting plans we have for the future.

React is so powerful that it can be used for more than frontend development. E.g. creating UI programmatically in the backend using a rule-based system or machine learning is another use case where React can serve as the best fit. Similarly, documentation earlier used to have only .md files but now it also includes .mdx file that contains React code. To fulfill such use cases, developers need to understand the internals of React and the tooling around it. Some great sources are popular codebases such as create-react-app, Next.js, etc. In this talk, I will share the lessons we learnt while creating a framework that achieves more than web development using React. Firstly, I will cover how create-react-app codebase is the best codebase to understand how webpack, babel, eslint, typescript etc. can be used alongside React. Secondly, I will share how Next.js teaches us to create a js framework where we can write backend and frontend in the same file and still be able to separate the two during calls. Thirdly, I will share how our framework supports plugins, i.e. the React code resides in multiple repositories but all of this code can share a single React runtime inside the browser. This is a very advanced use of React that cannot be achieved by code splitting using React.lazy. This talk will enable developers to use React for more than frontend development.

Server components is an exciting new feature introduced in React 18. It lets us leverage the fast performance of the server by offloading work behind a component to the server. Why would we want to do that? because server has direct access to data source .so fetching data, making aPI calls would be really fast on the server. The most amazing thing about RSC is that they add 0 kb to the client bundle. So not only RSC reduces the bundle-size but will also improve page load times, eventually providing better user experience. In this talk I will be talking about what react server components are, why do we need them . RSC is often confused with SSR but we will see how they are fundamentally different. We will create a small react application using server components and see the performance benefits. We will also see the challenges we might face when we use RSC in our normal react application. Finally we deep dive into React’s brain and see how things are happening under the hood.

This talk shares how to achieve Server-side rendering using WebAssembly and WASMEdge which is a WebAssembly Runtime. The talk also covers the benefits of using WebAssembly to achieve Server Side Rendering. The talk will also cover a demo on how to launch a React application using the WasmEdge runtime.

In this talk, we will take a novel and original look into some of the unexpected behaviors in a React codebase and the anti-patterns that cause them. We discovered them while building a new full-stack web development framework on top of React.

React and the JavaScript ecosystem seems to be constantly changing. Wherever we look, there are new libraries and frameworks. These new tools always lead to learning concepts that are often non-transferable knowledge. What if I told you that by learning standard web APIs, relearning the web, and getting a bunch of transferable knowledge, you can also start using a fantastic new addition to the React ecosystem: Remix!

In this talk we will learn what is Slots and what does it mean to the React ecosystem, what's the current state and the future.

If you think that static rendering is limited to generic and public content that is the same for every user of your website, this talk is for you. Segmented Rendering is a new pattern for the Jamstack that lets you personalize content, statically, without any sort of client-side rendering or per-request Server-Side Rendering. Get the best possible performances for use cases such as theming, internationalization, A/B testing, multi-tenancy, and start treating your users right!