Once again it is time for Europes biggest [React](https://hackernoon.com/tagged/react) [conference](https://hackernoon.com/tagged/conference) 🎉. I would like to give you my experience with the conference as well as a rough overview of the talks (will add the video links once they are uploaded). I hope it helps you to get a better understanding why you should come visit next year too and which talks to have a detailed look at. ### The evening before The organizers of React-Europe had an [opening party](https://medium.com/@ReactEurope/reacteurope-bar-night-party-on-the-17th-of-may-for-reacteurope-attendees-e0744e80702) the day before the conference at a bar near the venue. It was pretty cool; we got free drinks until about 22:00 and afterward a lot of pretty awesome people just bought pitchers and went around to help everyone out. [Daniel Banck](https://medium.com/@dbanck) and I were there for about 4 hours, and it was hard to leave because we had so many great conversations with a lot of different people. **Video** * Coming soon #### What I Learned Benchmarking React by [Dominic Gannaway](https://medium.com/@trueadm) **TL;DR** * Rollups flat modules helped react to get a ~10% improvement in bundle size and load time * Rollup is a good match for improving performance in libraries * [Google Lighthouse](https://developers.google.com/web/tools/lighthouse/) is a great tool for performance benchmarking  **Video** * Coming soon #### Building High-Quality JavaScript Tools by [Christoph Pojer](https://medium.com/@cpojer) **TL;DR** * New features and improved performance made Jest a lot better and increased the adoption to over 100 companies * Snapshot tests are great for getting a good coverage and are being compared with having no tests rather then with conventional tests. * Jest moved to a modular structure, and the modules are already used in different open source projects  **Video** * Coming soon #### La nouvelle vague by [Sunil Pai](https://medium.com/@threepointone) **(“**[π](https://www.utf8icons.com/character/960/greek-small-letter-pi)”) **TL;DR** * The new wave is the movement from runtimes to compilers * Good examples are [Gatsby](https://github.com/gatsbyjs/gatsby), [next.js](https://github.com/zeit/next.js), [relay](https://github.com/facebook/relay) & [prepack](https://github.com/facebook/prepack) which leverage on compilers to reduce their runtime * “If you can’t introduce a library gradually, it’s dead on arrival”  **Video** * Coming soon #### Worse is Better: The Upside of JavaScript Fatigue by [Kevin Lacker](https://medium.com/@lacker) **TL;DR** * Simplicity is the most important attribute of a software system to determine its success (e.g. React only taking the View layer) * Simplicity => Popularity => Contributors (= Fatigue, because new projects pop up very often)  **Video** * Coming soon #### What WebAssembly means for React by [Lin Clark](https://medium.com/@linclark) **TL;DR** * Current state of Web Assembly may not allow significant performance improvements if the React Reconciler gets ported to Web Assembly * Down the line, there could be major improvements to the performance & ecosystem by improved APIs and tooling  **Video** * Coming soon #### Practical Confidence by [Adam Perry](https://twitter.com/dika10sune) **TL;DR** * “Types are tests for the structure of your data” * Type annotations reduce the cognitive overhead of figuring out the type of variables in your code, also through editor integration * Flow has a lot of inference features, so only the exports of a module need to be typed most of the time  **Video** * Coming soon #### Imperfection by [Cheng Lou](https://twitter.com/_chenglou) **TL;DR** * Software Engineering means making trade-offs; choosing the right ones is an art * Doing 80% with 20% of the efforts is good enough most of the times. This only applies if your foundation (language, type system, etc.) is solid (100%) * “Grow your slopiness budget by approaching certain parts as e.g. the foundation with a 100% mentality  **Video** * Coming soon #### Maximally Modular Apps with React Navigation by [Eric Vicenti](https://medium.com/@ericvicenti) **TL;DR** * demonstrated the power of [react-navigation](https://github.com/react-community/react-navigation) with [a small demo app](https://github.com/ericvicenti/swag-store) * react-navigation can be used in web and native  **Video** * Coming soon #### How Streaming Can Supercharge React by [**Sasha Aickin**](http://xander76) **TL;DR** * Time to first render and time to first interaction is important for a business * Client Side loading gives a bad user experience, Server Side Rendering is better but has a long time of non-interactive sites * Chunked Rendering allows different parts of the application to load individually, which also leads to better fault tolerance  **Video** * Coming soon #### ⚡ Talks * **return null; by Joshua Comeau**: Using components for other things than rendering UI can be valuable, too * **Fancy Footwork by Brendan Moore, Sarah Mogin and Serge Rose**: They build a CMS frontend with React and Redux which embraces modular design principles * **ShoutemUI by the Shoutem team:** They built a market place for React Native extensions (think authentication) * **Thousand ways to navigate in React Native by Charles Mangwa:** He introduced [react-router-navigation](https://github.com/LeoLeBras/react-router-navigation), a way to navigate in React Native just using components * **Detox by** [Tal Kol](https://medium.com/@talkol) & [Rotem Mizrachi-Meidan](https://medium.com/@rotemmiz): They created an E2E testing framework for React Native that is very easy to use, stable and fast * **Devtools for GraphQL by Danielle Man:** The Apollo team developed a Chrome Extension for developing with Apollo with features like Query watching and Store inspection  ### Second Day And once again [Brent Vatne](https://medium.com/@notbrent) guided us through the day. In the morning people came in a bit later than yesterday, a lot have gathered yesterday evening at the frog, where we already met the day before. #### Next generation state management by [Michel Weststrate](https://medium.com/@mweststrate) **TL;DR** * He introduce [mobx-state-tree](https://github.com/mobxjs/mobx-state-tree), a new way to use the graph-based advantages of MobX and combine them with the tree based advantages of Redux * He demoed the Redux TODO MVC App with an exchanged MobX reducer and displayed features like time traveling  **Video** * Coming soon #### Composition by [Nik Graf](https://medium.com/@nikgraf) **TL;DR** * State in composition is error prone. Therefore we should embrace function programming paradigms as higher-order functions & components * He showed how the [polished](https://github.com/styled-components/polished) library and an app with Apollo that used HOC for loading screens  **Video** * Coming soon #### The making of Twitter Lite by [Nicolas Gallagher](https://medium.com/@necolas) **TL;DR** * Twitter Light has a better performance in load time as well as data consumption and time to interaction * It doesn’t use Server Side Rendering; he explained why in detail * Think about disposability of parts of your application while designing the system  **Vide0** * Coming soon #### ⚡ Talks * **Snack by** [**Brent Vatne**](https://medium.com/@notbrent)**:** Use react-native in the browser on [https://snack.expo.io/](https://snack.expo.io/) * **React Native Components in Android Apps by** [**Petter Hesselberg**](https://medium.com/@petterhesselberg)**:** See the demo at [https://github.com/petterh/react-europe-demo](https://github.com/petterh/react-europe-demo) * **Quantifying Best Practices by Jackson Hamburger and** [**Louis Antonelli**](https://medium.com/@louisantonelli)**:** How pure components and key props improve your performance * **Leveraging code-splitting by** [**Glenn Reyes**](https://medium.com/@glennreyes)**:** Intro to dynamic import statements with babel and webpack * **Smarter code-splitting and preloading by Brandon Dail:** A brief and good introduction to [react-loadable](https://github.com/thejameskyle/react-loadable) and [react-perimeter](https://github.com/aweary/react-perimeter) * **Rise of low-configuration tools by** [**Karl Horky**](https://medium.com/@karlhorky)**:** Configuration leads to many bad effects for open source; add them only when really needed  #### Exploring Relay Modern by [Lee Byron](https://medium.com/@leeb) **TL;DR** * Relay Modern shifts assumptions from dynamic queries to static ones, allowing compilers to do ahead of time optimizations * These optimizations lead to better performance and less network traffic (900ms win on Facebook Marketplace app) * You can introduce Relay Moderns API step by step and once you finished the conversion switch to it completely  **Video** * Coming soon #### Animating the Virtual DOM by [Sarah Drasner](https://medium.com/@sarah_edo) **TL;DR** * Animation is very important to keep the users attention and reduce perceived waiting times * For every job there is the right tool, CSS-in-JS for simple transitions, [GreenSock](https://github.com/greensock/GreenSock-JS) for sequencial & complex movements, [React-Motion](https://github.com/chenglou/react-motion) for simple, physics based animations  **Video** * Coming soon ### Credits Special thanks to [Daniel Banck](https://medium.com/@dbanck) for being a partner in crime at this conference and providing all the images 💙 _Want to hear more from me? 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