#react

Ivan’s first attempts at performance debugging were chaotic. He would see a slow interaction, try a random optimization, see that it didn't help, and keep trying other optimizations until he found the right one (or gave up).
Back then, Ivan didn’t know how to use performance devtools well. He would do a recording in Chrome DevTools or React Profiler, poke around it, try clicking random things, and then close it in frustration a few minutes later. Now, Ivan knows exactly where and what to look for. And in this workshop, Ivan will teach you that too.
Here’s how this is going to work. We’ll take a slow app → debug it (using tools like Chrome DevTools, React Profiler, and why-did-you-render) → pinpoint the bottleneck → and then repeat, several times more. We won’t talk about the solutions (in 90% of the cases, it’s just the ol’ regular useMemo() or memo()). But we’ll talk about everything that comes before – and learn how to analyze any React performance problem, step by step.
(Note: This workshop is best suited for engineers who are already familiar with how useMemo() and memo() work – but want to get better at using the performance tools around React. Also, we’ll be covering interaction performance, not load speed, so you won’t hear a word about Lighthouse 🤐)

React Testing Library is a great framework for React component tests because there are a lot of questions it answers for you, so you don’t need to worry about those questions. But that doesn’t mean testing is easy. There are still a lot of questions you have to figure out for yourself: How many component tests should you write vs end-to-end tests or lower-level unit tests? How can you test a certain line of code that is tricky to test? And what in the world are you supposed to do about that persistent act() warning?
In this three-hour workshop we’ll introduce React Testing Library along with a mental model for how to think about designing your component tests. This mental model will help you see how to test each bit of logic, whether or not to mock dependencies, and will help improve the design of your components. You’ll walk away with the tools, techniques, and principles you need to implement low-cost, high-value component tests.
Table of contents
- The different kinds of React application tests, and where component tests fit in
- A mental model for thinking about the inputs and outputs of the components you test
- Options for selecting DOM elements to verify and interact with them
- The value of mocks and why they shouldn’t be avoided
- The challenges with asynchrony in RTL tests and how to handle them
Prerequisites
- Familiarity with building applications with React
- Basic experience writing automated tests with Jest or another unit testing framework
- You do not need any experience with React Testing Library
- Machine setup: Node LTS, Yarn

We're going to be using Nx and some its plugins to accelerate the development of this app.
Some of the things you'll learn:
- Generating a pristine Nx workspace
- Generating frontend React apps and backend APIs inside your workspace, with pre-configured proxies
- Creating shared libs for re-using code
- Generating new routed components with all the routes pre-configured by Nx and ready to go
- How to organize code in a monorepo
- Easily move libs around your folder structure
- Creating Storybook stories and e2e Cypress tests for your components
Table of contents: 
- Lab 1 - Generate an empty workspace
- Lab 2 - Generate a React app
- Lab 3 - Executors
- Lab 3.1 - Migrations
- Lab 4 - Generate a component lib
- Lab 5 - Generate a utility lib
- Lab 6 - Generate a route lib
- Lab 7 - Add an Express API
- Lab 8 - Displaying a full game in the routed game-detail component
- Lab 9 - Generate a type lib that the API and frontend can share
- Lab 10 - Generate Storybook stories for the shared ui component
- Lab 11 - E2E test the shared component

There are many advantages to using GraphQL as a datasource for frontend development, compared to REST APIs. We developers in example need to write a lot of imperative code to retrieve data to display in our applications and handle state. With GraphQL you cannot only decrease the amount of code needed around data fetching and state-management you'll also get increased flexibility, better performance and most of all an improved developer experience. In this workshop you'll learn how GraphQL can improve your work as a frontend developer and how to handle GraphQL in your frontend React application.

Are you a React developer trying to get the most benefits from TypeScript? Then this is the workshop for you.
In this interactive workshop, we will start at the basics and examine the pros and cons of different ways you can declare React components using TypeScript. After that we will move to more advanced concepts where we will go beyond the strict setting of TypeScript. You will learn when to use types like any, unknown and never. We will explore the use of type predicates, guards and exhaustive checking. You will learn about the built-in mapped types as well as how to create your own new type map utilities. And we will start programming in the TypeScript type system using conditional types and type inferring.

In this workshop, you will get a first-hand look at what end-to-end type safety is and why it is important. To accomplish this, you’ll be building a GraphQL API using modern, relevant tools which will be consumed by a React client.
Prerequisites: 
-
Node.js
installed on your machine (12.2.X / 14.X)
- It is recommended (but not required) to use
VS Code
for the practical tasks
- An IDE installed (VSCode recommended)
- (Good to have)*A basic understanding of Node.js, React, and TypeScript

With the release of React 18 we finally get the long awaited concurrent rendering. But how is that going to affect your application? What are the benefits of concurrent rendering in React? What do you need to do to switch to concurrent rendering when you upgrade to React 18? And what if you don’t want or can’t use concurrent rendering yet?
There are some behavior changes you need to be aware of! In this workshop we will cover all of those subjects and more.
Join me with your laptop in this interactive workshop. You will see how easy it is to switch to concurrent rendering in your React application. You will learn all about concurrent rendering, SuspenseList, the startTransition API and more.

ReactJS is wildly popular and thus wildly supported. TypeScript is increasingly popular, and thus increasingly supported.
The two together? Not as much. Given that they both change quickly, it's hard to find accurate learning materials.
React+TypeScript, with JetBrains IDEs? That three-part combination is the topic of this series. We'll show a little about a lot. Meaning, the key steps to getting productive, in the IDE, for React projects using TypeScript. Along the way we'll show test-driven development and emphasize tips-and-tricks in the IDE.

In this workshop, you'll learn how to build your first full stack dapp on the Ethereum blockchain, reading and writing data to the network, and connecting a front end application to the contract you've deployed. By the end of the workshop, you'll understand how to set up a full stack development environment, run a local node, and interact with any smart contract using React, HardHat, and Ethers.js.

The distinction between server state and client state in our applications might be a new concept for some, but it is very important to understand when delivering a top-notch user experience. Server state comes with unique problems that often sneak into our applications surprise like:
- Sharing Data across apps
- Caching
&
Persistence
- Deduping Requests
- Background Updates
- Managing “Stale” Data
- Pagination
&
Incremental fetching
- Memory
&
Garbage Collection
- Optimistic Updates
Traditional “Global State” managers pretend these challenges don’t exist and this ultimately results in developers building their own on-the-fly attempts to mitigate them.
In this workshop, we will build an application that exposes these issues, allows us to understand them better, and finally turn them from challenges into features using a library designed for managing server-state called React Query.
By the end of the workshop, you will have a better understanding of server state, client state, syncing asynchronous data (mouthful, I know), and React Query.

React keeps on evolving and making hard things easier for the average developer.
One case, where React was not particularly hard but very repetitive, is working with AJAX request. There is always the trinity of loading, success and possible error states that had to be handled each time. But no more as the `
<
Suspense /
>
` component makes life much easier.
Another case is performance of larger and complex applications. Usually React is fast enough but with a large application rendering components can conflict with user interactions. Concurrent rendering will, mostly automatically, take care of this.
You will learn all about using
<
Suspense /
>
, showing loading indicators and handling errors. You will see how easy it is to get started with concurrent rendering. You will make suspense even more capable combining it with concurrent rendering, the `useTransition()` hook and the
<
SuspenseList /
>
component.

The addition of the hooks API to React was quite a major change. Before hooks most components had to be class based. Now, with hooks, these are often much simpler functional components. Hooks can be really simple to use. Almost deceptively simple. Because there are still plenty of ways you can mess up with hooks. And it often turns out there are many ways where you can improve your components a better understanding of how each React hook can be used.
You will learn all about the pros and cons of the various hooks. You will learn when to use useState() versus useReducer(). We will look at using useContext() efficiently. You will see when to use useLayoutEffect() and when useEffect() is better.

Join us for a 3-hour workshop that dives into the world of creative React development using Codux. Participants will explore how a visually-driven approach can unlock creativity, streamline workflows, and enhance their development velocity. Dive into the features that make Codux a game-changer for React developers. The session will include hands-on exercises that demonstrate the power of real-time rendering, visual code manipulation, and component isolation all in your source code.
Table of the contents: 
- Download
&
Setup: Getting Codux Ready for the Workshop
- Project Picker: Cloning and Installing a Demo Project
- Introduction to Codux Core Concepts and Its UI
- Exercise 1: Finding our Feet
- Break
- Exercise 2: Making Changes While Staying Effective
- Exercise 3: Reusability and Edge Case Validation
- Summary, Wrap-Up, and Q
&
A

Passwordless authentication may seem complex, but it is simple to add it to any app using the right tool. There are multiple alternatives that are much better than passwords to identify and authenticate your users - including SSO, SAML, OAuth, Magic Links, One-Time Passwords, and Authenticator Apps.
While addressing security aspects and avoiding common pitfalls, we will enhance a full-stack JS application (Node.js backend + React frontend) to authenticate users with OAuth (social login) and One Time Passwords (email), including:
- User authentication - Managing user interactions, returning session / refresh JWTs
- Session management and validation - Storing the session securely for subsequent client requests, validating / refreshing sessions
- Basic Authorization - extracting and validating claims from the session token JWT and handling authorization in backend flows
At the end of the workshop, we will also touch other approaches of authentication implementation with Descope - using frontend or backend SDKs.

You’ve built apps with frontend frameworks before? - Then you surely came across the terms ""declarative"" and “reactive”. Since React got released in 2013, most modern UI frameworks or libraries want to be it, but what do these terms actually mean? And what’s the difference between “declarative” and “imperative” code?
It took me a long time to grasp these concepts - but when I finally did, I saw frontend frameworks in a totally new light! And I hope you will feel the same after this talk.
In this very interactive workshop, we’ll delve into a lot of code examples to deeply understand the terms - with examples using vanilla JavaScript, React and Svelte. But the learnings will be universal. After this talk you’ll be able to confidently join discussions about the ""declarative"" and ""reactive"" nature of any new package or library.

React Testing Library is a great framework for React component tests because there are a lot of questions it answers for you, so you don’t need to worry about those questions. But that doesn’t mean testing is easy. There are still a lot of questions you have to figure out for yourself: How many component tests should you write vs end-to-end tests or lower-level unit tests? How can you test a certain line of code that is tricky to test? And what in the world are you supposed to do about that persistent act() warning?
In this three-hour workshop we’ll introduce React Testing Library along with a mental model for how to think about designing your component tests. This mental model will help you see how to test each bit of logic, whether or not to mock dependencies, and will help improve the design of your components. You’ll walk away with the tools, techniques, and principles you need to implement low-cost, high-value component tests.
Prerequisites:
- Familiarity with building applications with React
- Basic experience writing automated tests with Jest or another unit testing framework
- You do not need any experience with React Testing Library
- Machine setup: Node LTS, Yarn

We know that React is for the web and React Native is for Android and iOS. But have you heard of react-native-web—for writing an app for Android, iOS, and the web in one codebase? Just like React Native abstracts away the details of iOS and Android, React Native Web extracts away the details of the browser as well. This opens up the possibility of even more code sharing across platforms.
In this workshop you’ll walk through setting up the skeleton for a React Native Web app that works great and looks awesome. You can use the resulting codebase as a foundation to build whatever app you like on top of it, using the React paradigms and many JavaScript libraries you’re used to. You might be surprised how many types of app don’t really require a separate mobile and web codebase!
What's included
1. Setting up drawer and stack navigators with React Navigation, including responsiveness
2. Configuring React Navigation with URLs
3. Setting up React Native Paper including styling the React Navigation drawer and headers
4. Setting up a custom color theme that supports dark mode
5. Configuring favicons/app icons and metadata
6. What to do when you can’t or don’t want to provide the same functionality on web and mobile
Prerequisites
- Familiarity with building applications with either React or React Native. You do not need to know both.
- Machine setup: Node LTS, Yarn, be able to successfully create and run a new Expo app following the instructions on
https://docs.expo.dev/get-started/create-a-new-app/

In this workshop, you will learn how to create a Custom Component System from scratch in React, and take it to the next level.
You will learn best practices when building a Component System, as well as the tools that you can use to be a more effective collaborator with other cross-functional teams.
What's included
1. Introduction
2. Learn the fundamentals of a Component System
3. Setting up the development environment
4. Importing fonts
5. Choosing a base React Component Library
6. Writing our first components
7. Setting up a centralized theme
8. Writing custom styles to inject to our components
9. Injecting icons to our components
10. Adding hooks
11. Making components responsive
12. Adding dark mode
13. Deploying your Component System
14. Exporting your Component System to a design tool
15. Prototyping with your production components

In this workshop, we'll take a tour through the most effective approaches to building out scalable UI components that enhance developer productivity and happiness :-) This will involve a mix of hands-on exercises and presentations, covering the more advanced aspects of the popular styled-components library, including theming and implementing styled-system utilities via style props for rapid UI development, and culminating in how you can build up your own scalable custom component library.
We will focus on both the ideal scenario---where you work on a greenfield project---along with tactics to incrementally adopt a design system and modern approaches to styling in an existing legacy codebase with some tech debt (often the case!). By the end of the workshop, you should feel that you have an understanding of the tradeoffs between different approaches and feel confident to start implementing the options available to move towards using a design system based component library in the codebase you work on.
Prerequisites:
- Familiarity with and experience working on large react codebases
- A good understanding of common approaches to styling in React

In this workshop, you will integrate a decoupled Gatsby Shopify website into Storyblok real-time visual editor.
1. Connect Gatsby with Shopify and build the catalog
2. Build the shopping Card functionality using shopify-buy
3. Connect Gatsby with Storyblok
4. Build editable components for the Storyblok visual editor, including Shopify products and Collections
Prerequisites
Computer ready for Gatsby.
Workshop level
React and Gatsby intermediate.

In this workshop you’ll learn why we created FlashList at Shopify and how you can use it in your code today. We will show you how to take a list that is not performant in FlatList and make it performant using FlashList with minimum effort. We will use tools like Flipper, our own benchmarking code, and teach you how the FlashList API can cover more complex use cases and still keep a top-notch performance.
You will know:
- Quick presentation about what FlashList, why we built, etc.
- Migrating from FlatList to FlashList
- Teaching how to write a performant list
- Utilizing the tools provided by FlashList library (mainly the useBenchmark hook)
- Using the Flipper plugins (flame graph, our lists profiler, UI
&
JS FPS profiler, etc.)
- Optimizing performance of FlashList by using more advanced props like `getType`
- 5-6 sample tasks where we’ll uncover and fix issues together
- Q
&
A with Shopify team

Anybody can write code that “works.” But what makes the best engineers stand out is their ability to create solutions that are clear, concise, testable and easy to understand and maintain. Join us as we explore two of React’s most powerful tools for well-architected solutions by starting with a suboptimal game codebase and refactoring it using industry best practices such as custom hooks, higher-order components (HOCs) and contexts.
- Introduction of the initial implementation and description of its issues.
- Presentation of the tools available to improve the code base.
- The mindset behind architecting clean solutions and refactoring.
- Highlevel passthrough of the code and creation of the plan.
- Extraction of code into utility functions.
- Extraction of state and effects into custom hooks.
- Grouping behavior into HOC.
- Creation of root level context and child components cleanup.
- Result overview and discussion of possible future improvements.
- How to keep your code clean, rules to follow and limitations to impose.
Prerequisites
A computer with git installed and a GitHub account.

Does your React app need to efficiently display lots (and lots) of data in a grid? Do your users want to be able to search, sort, filter, and edit data? AG Grid is the best JavaScript grid in the world and is packed with features, highly performant, and extensible. In this workshop, you’ll learn how to get started with AG Grid, how we can enable sorting and filtering of data in the grid, cell rendering, and more. You will walk away from this free 3-hour workshop equipped with the knowledge for implementing AG Grid into your React application.
We all know that rolling our own grid solution is not easy, and let's be honest, is not something that we should be working on. We are focused on building a product and driving forward innovation. In this workshop, you'll see just how easy it is to get started with AG Grid.
Prerequisites: 
Basic React and JavaScript
Workshop level:
Beginner

Learn how to build web apps from design in Figma to deploying to AWS while moving very fast.

So, you have a killer React app you've built and want to take it from your web browser to the App Store. Sure, there are a lot of options here, but most will require you to maintain separate apps for each platform. You want your codebase to be as close as possible across Web, Android, and iOS. Thankfully, with Capacitor, you can take your existing web app and quickly create native iOS and Android apps for distribution on your favorite App Store!
This workshop is aimed at intermediate developers that have an existing React application, or are interested in mobile development with React. We will go over:
What is Capacitor
How does it compare to other cross-platform solutions
Using Capacitor to build a native application using your existing web code
Tidying up our application for distribution on mobile app stores with naming conventions, icons, splashscreens and more.

Ready to kickstart your freelance career or just getting started on your freelance journey? You’re in the right spot. Learn from the world’s largest fully distributed workforce in the world.
The independent talent movement is the future of work. If you’re considering leaving full-time employment for a career as a freelancer, now is the time to find your successful space in the independent talent workforce.
More people are working freelance
today than ever before, with the freelance marketplace now contributing $1.2 trillion to the US economy. Some of the most
in-demand roles
for freelancers right now are senior developers with professional experience in React, Python, Blockchain, QA, and Node.js.
This workshop will help you design a sustainable and profitable full-time (or part-time) freelancing/contracting career. We will give you tools, tips, best practices, and help you avoid common pitfalls.
At the end of the workshop there will be a Q
&
A session with a Freelance Developer who can answer your questions and provide insights and tips into their own success.
During the Workshop break, we will be running a speed-coding challenge! At the end of the workshop, we will award a prize for the winner and display the leaderboard.
We will have you login to our portal and complete the challenge as fast as you can to earn points. Points are assigned based on difficulty and the speed at which you solve the tasks. In case you complete all tasks, you get extra points for the remaining time. You’ll see your score, ranking, and the leaderboard once you complete the challenge.
We will be giving away three Amazon Gift Cards ($200, $100, $75) for the top three winners.

As a developer, you need to deliver fast, and you simply don't have the time to constantly think about security. Still, if something goes wrong it's your job to fix it, but security testing blocks your automation, creates bottlenecks and just delays releases, especially with graphQL...but it doesn't have to...
NeuraLegion's developer-first Dynamic Application Security Testing (DAST) scanner enables developers to detect, prioritise and remediate security issues EARLY, on every commit, with NO false positives / alerts, without slowing you down.
Join this workshop to learn different ways developers can access NeuraLegion's DAST scanner
&
start scanning without leaving the terminal!
We will be going through the set up end-to-end, whilst setting up a pipeline for a vulnerable GraphQL target, running security tests and looking at the results.
Table of contents:
- What developer-first DAST (Dynamic Application Security Testing) actually is and how it works
- See where and how a modern, accurate dev-first DAST fits in the CI/CD
- Integrate NeuraLegion's scanner with GitHub Actions
- Understand how modern applications, GraphQL and other APIs and authentication mechanisms can be tested
- Fork a repo, set up a pipeline, run security tests and look at the results

Blitz.js is the Fullstack React Framework. It's heavily inspired Ru on Rails and is focused on making you as productive as possible. It's built on Next.js and adds all the missing pieces you need for building a fullstack app with a database. By far the biggest innovation of Blitz is the new "Zero-API" data layer that abstracts away the API so you don't have to mess with REST or GraphQL APIs!
Simon will introduce all the important parts
&
guide you through getting started with Blitz, so you'll know if you might want to use it or not.

Content is a crucial part of what you build on the web. Modern web technologies brings a lot to the developer experience in terms of building content-driven sites, but how can we improve things for editors and content creators? In this workshop you’ll learn how use Sanity.io to approach structured content modeling, and how to build, iterate, and configure your own CMS to unify data models with efficient and delightful editor experiences. It’s intended for web developers who want to deliver better content experiences for their content teams and clients.

When building an app, there are many options choices developers need to make. Is it a web app? Does need to be a native app? What should I use for UI? In this workshop will look at how to make use of Ionic for building your app and how to deploy it to not only the web, but native as well.

Join Sentry’s Evan Purkhiser and David Wang as they walk through Sentry’s 230k LoC Typescript/React codebase. They’ll tell war stories of the good, the bad, and the ugly. Gaze in wonder at their modern usage of Typescript, react hooks, and styled components. Recoil in disgust at their legacy Reflux usage and perplexing Webpack configuration. Step away from the workshop with a working knowledge of techniques to keep a large-scale frontend codebase modern and maintainable.

In this workshop, we'll build out a fully functional website and integrated blog with Next.js and Strapi.
Table of contents:
- An introduction to Headless CMS and supported architectures
- Getting up and Running with Strapi and Next.js
- Integrating Blog functionality into a Next.js app
- Deploying your Next.js and Strapi Apps Bonus
- Implementing content previews with Next.js
Prerequisites:
Basic React Knowledge Basic knowledge of Node.js and npm Basic Web Concepts.

Svelte is a new prominent JS framework exposing “write less do more” philosophy. During this workshop you will get proficiency as a Svelte developer. 
We will be building an app that mimics the famous Q
&
A website stackoverflow.com. Will start developing from simple front end components, later we'll connect it to a real running backend and then test it and optimise for production.
Attending a workshop is the fastest way to acquire a body of knowledge about building web apps with Svelte. 

Did you ever work in a monolithic Next.js app? I did and scaling a large React app so that many teams can work simultaneously is not easy. With micro frontends you can break up a frontend monolith into smaller pieces so that each team can build and deploy independently. In this workshop you'll learn how to build large React apps that scale using micro frontends.

A lot has changed in the world of state management in React the last few years. Where Redux used to be the main library for this, the introduction of the React Context and Hook APIs has shaken things up. No longer do you need external libraries to handle both component and global state in your applications. In this workshop you'll learn the different approaches to state management in the post-Redux era of React, all based on Hooks! And as a bonus, we'll explore two upcoming state management libraries in the React ecosystem.

Essential topics covered:
- Setting up and developing a react project using create-react-app
- Basic JSX syntax
- The declarative philosophy, what props and state are
- Function components

In this workshop, we’ll look at some of the approaches and techniques that can be applied when making refactors or adding new features to a legacy React codebase to bring it inline with the latest approaches. We’ll cover topics such as how to use React Hooks to share component logic in a way that will allow reuse in class components; how to incrementally introduce other patterns to a React Redux app; and how to build in flexible UI components via abstractions where we are tied to some global CSS or a component library. Along the way, we’ll touch on many React patterns and state management approaches with the ultimate aim of being able to evaluate these options and let our requirements drive the architecture in moving towards a more robust and maintainable codebase.