We’re bringing world class React hackers to Bratislava to let them share unique insights.

Creators of the most popular open source libraries and world-class JS experts, you can trust us to invite the best of them.

ReactiveConf

The frontend landscape changes at a relentless pace. New ideas seem to appear every month. How can you possibly keep up? I'm on the Firefox Developer Tools team, and we are starting to move towards React and Redux for our frontend. I will explain these choices, the reasons behind them, and how we're migrating old code. Our minds can only keep up with a certain level of abstraction, and it's important to choose abstractions that solve fundamental problems rather than shallow ones. The right abstractions will make an order of magnitude difference in power and simplicity, and the wrong ones can be deadly. It's important to estimate the cost of every abstraction, and be ruthless about keeping it as simple as possible.


Works for Mozilla on the Firefox Developer Tools, mostly trying to make debugging JavaScript better. He's spent the last 8 years studying programming languages like Lisp and Scheme, and trying to bring various ideas to JavaScript. He likes to write in-depth articles about interesting programming ideas. Most of his free time is now happily dedicated to his daughter

Abstracting just enough

Imagine how easy building your web application would be if all of your data was available in-memory on the client. Falcor lets you to code that way. 

Falcor is the open-source, JS data access framework that powers Netflix. Falcor lets you represent all of your cloud data sources as one virtual JSON model on the server. On the client, Falcor makes it appear as if the entire JSON model is available locally and allows you to access data the same way you would from an in-memory JSON object. Falcor retrieves the model data you request from the cloud on-demand, transparently handling all the network communication and keeping the server and client in sync. 

Falcor is not a replacement for your MVC framework, your database, or your application server. Falcor fits seamlessly into your existing stack and lets the layers communicate more efficiently. 

Get an inside look at the innovative data platform that powers the Netflix UIs and the new UI design patterns it enables. Learn more how Falcor powers Netflix, and how you can integrate into your existing stack.

Bind to the cloud with Falcor

As programs get bigger, they also become more complex and harder to understand. We all think ourselves pretty clever, of course, but we are mere human beings, and even a moderate amount of chaos tends to baffle us. And then it all goes downhill. Working on something you do not really understand is a bit like cutting random wires on those time-activated bombs they always have in movies. If you are lucky, you might get the right one ― especially if you are the hero of the movie and strike a suitably dramatic pose ― but there is always the possibility of blowing everything up.

Daniel Steigerwald is the Creator of Este, dev stack and starter kit for React/Flux universal web applications. Angel developer, Google Developer Expert, libertarian.

Functional Programming in JavaScript. What, Why, and How

Even though I believe programming UI can be made simple, right now, front-end is hard. We’re at the very beginning of our path to the future web: simple, error-prone, pleasant to use. In this talk, we’ll see how practices we have today in back-end programming, such as immutability, use of database engines, query languages and functional programming, can help us build JavaScript UIs. Examples include DataScript, Elm, Om, ClojureScript, Relay and more

For the past ten years Nikita Prokopov has been building web interfaces, backends and distributed systems in Clojure, Erlang, Python, Java.

How immutability, functional programming, databases and reactivity change front-end

With the push towards writing CSS in JavaScript within the React community, CSS Modules have suddenly emerged as a surprisingly popular alternative that still allow us to maintain our connection with the CSS community. 

Do we have to give up writing CSS in JavaScript? Are we clinging to the past, or do CSS Modules offer a new way forward for the entire web community? In this talk we'll examine both the history and potential future of CSS Modules, and hopefully inspire the next generation of styling in React.

The case for CSS modules

We tried swapped out D3's DOM model in favor of React. The result? Love at first iteration. Building a data visualization library as React components means that you can reclaim your SVG as declarative markup, NPM install visualizations directly into your project (can't do that with bl.ocks!), fork them, remix them and file issues against them. It also meant completely rethinking how animations are done, since D3's animation model relies on its DOM model. Come learn the API, and what it means for the future of interactive data visualization.

Victory.js - A powerful data visualization library for ReactJS

The one way flow of flux has pushed us in the right direction, but we are still evolving what makes up that flow. Cerebral is a project that separates storing state and producing state with a functional flow defining API called signals.

State, UI and the stuff in between

Functional programming gives developers better ideas on how the application will react, more expected outputs, and less time needed for debugging. Immutability is one of the key points for functional programming, I'll show you some of the things we can improve on the front-end to make the code more immutable and functional.

Front‐end can be more functional

Let's zoom out of the reactive front-end story to see the big picture. How data and events propagate between clients and servers? What if clients are mobile and connections are intermittent? 
What about offline work? Can we cache our data? What if we need to act in real time? 
Welcome to the world of distributed mutable state, also known as ""hell"". Way too often, existing methods pretend that we act in a single point, at a single moment of time, alone (think ACID). 
One approach to truly asynchronous thinking is the math apparatus known as CRDT (Commutative/Convergent Replicated Data Types). I will tell how CRDT can be practically used to resolve some of the challenges mentioned.

What do Reactive apps react to?

Reactive Extensions for JavaScript is evolving! Building on lessons learned from RxJava and RxMobile, Microsoft Netflix, Google, and the ReactiveX community have begun work on the next version of RxJS. This talk will enumerate the improvements we’ve made to increase speed, reduce memory, expose locations for extension, provide more debuggable call-stacks, and enable more readable flame charts.

RXJS Evolved

React is great and Flux is awesome. Running both on the server and client is even better! You've built your app with the latest and greatest tech stack, but will your app scale to millions of users? We created and open sourced Fluxible and other libraries that support Yahoo's high-traffic web applications. I'll share our learnings and go through best practices, performance concerns, and challenges of building robust and scalable web applications.

Universal React + Flux at scale

React is a great tool for synchronizing data with views on the client side. However, to achieve perfect real-time experience one also needs to synchronize server data with client data. Unfortunately the nowadays widely used REST-like API is rather suited to one-time fetches, usually resulting in stale client data. Reactive databases such as Firebase seek to be the solution to this problem. 

I will show how Firebase can be integrated with React (spoiler alert: it can be done in a beautiful way) to get what-you-see-is-what-it-really-is kind of UX and how the FLUX pattern helps us to keep database updates clean. Since Firebase-like databases are quite fresh and immature, you may get an inspiration for a nice Friday-night project here.

Integrating React with Reactive databases

The ability to express essential complexity in a simple way is crucial for any code-base. At Mendix we did an interesting discovery during the development of a complex MDD tool. React, mutable data structures and transparent reactive programming are a match made in heaven. We published a library that leverages these concepts; Mobservable. It helps you to write simple, declarative, yet highly efficient code. Your future code maintainers will love you for applying it.

React, transparent reactive programming and mutable data structures

The web is evolving out of the browser. With the rise of React Native for iOS, and the recently open sourced Android version, universal javascript is now about fully featured experiences across web, mobile devices and soon, it will be also about smart watches, TVs and beyond. 
Device fragmentation is about to explode and the need for write-once and run-everywhere is stronger than ever. The ability to maintain a single codebase of components and logic is currently a convenience but soon will be a necessity to keep up with the plethora of devices that our services will be accessed through. 

This talk explores these concepts and discusses the foundations of a developing a device-agnostic platform. By checking out various patterns and deployment techniques we are going to see how you can power all your devices by Javascript with confidence. Yes, even your washing machine!

Let's talk JavaScript

Engineers with experience using React for web coming who dive into mobile will feel at home quickly because the basic React API doesn't change. But building for mobile introduces a different way of thinking about the software that you create and React Native empowers you to embrace this rather than attempt to hide it from you: your primary mode of interaction is touch, animations are more common and are expected to be smooth and dynamically track your gestures, you actually have to think about how your app will handle offline / poor connectivity, what happens when the user backgrounds it and comes back, how to send push/local notifications and respond to them, how to stay at 60fps performance on a much less capable device with more demanding users, responding to the keyboard appearing and hiding - specifying different keyboard types, autocorrect/autocomplete, dealing with device orientation changes and status bar changes, app store deployment delays and more. I won't go into great detail about each of these points but will rather help you to build a mental map of the space and touch on solutions that React Native provides to handle these mobile-specific problems, in order for unknown unknowns can become known unknowns. So this talk is kind of to React Native what a maphack is to Starcraft, but totally not lame like that.

From React web to native mobile: mapping out the unknown unknowns

Imagine a world without side effects, where the only way to make things happen was to call functions whose return values described what you wanted done. What gets easier in that world? What gets harder? What would that mean for debugging? Testing? 

We don't have to wonder about these things, because this world already exists — and it compiles to JavaScript. It's the world of Elm, where there are no side effects, all functions are stateless, and all data is immutable. Elm embraces the concepts that make reactive programming great, and goes one step further to shed the error‐prone mutations and side effects that so often lead to incidental complexity and buggy code. 

NoRedInk has reaped the benefits of this approach since they began using Elm in production earlier in 2015. It's helped them scale and maintain a complex front-end code base that students use to answer millions of questions per day. Come see how refreshing this world can be!

Effects as Data

Learn how Facebook uses React Native and how we run the open source project.

Under The Hood of React Native

Dato is a new way of building applications, heavily inspired by Meteor/Firebase/Relay, but informed by functional, data-oriented programming techniques. 
The goal is to provide:
Seamless, permission-aware data synching between the sever and n-clients
Seamless, permission-aware rpc invocations
A more flexible, intuitive UI layer
Advanced tooling layer for time-traveling debuggers, state serialization, component layout, query editing, performance optimizations, and others.
Integration on the backend to stream into analytics, session replay, 3rd-party integration

Dato - functional way to build reactive applications

Creating validated forms is usually a troublesome experience. Most libraries used for building forms are complex and difficult to customize. As React plays nicely with functional approach, it can be easily used to create library for creating forms that is: a) simple and easy to understand b) customizable and extensible c) providing top user experience. I will present such library for building validated forms.

Form Validation made simple with React

d3 has been the de facto standard when it comes to data visualisations for a while now and React has recently emerged as the go-to library for building user interfaces. d3 and React are both data-centric libraries, making them a natural fit; d3 takes a data-driven approach and React aims to solve the problem of data changing over time in the context of building large applications. 
There have been various approaches documented on how to effectively use d3 and React together. In this talk, I will be going through a number of these approaches, talking about what I have learned from them and how I go about creating reusable chart components for large scale applications.

D3 with React

In the past two years, React and all the related projects completely changed our way of creating application by breaking all the rules and forcing us to redefine what we thought being "best practice". However, there is still an area that has not changed much : how we define the relationship between user input and application state. In this talk, I'll try to demonstrate that we can express this relationship in a simpler and more declarative way by using techniques from reactive programing and by combining React with RxJS.

Going reactive with React

If you’re like me, coming from web development, you find traditional mobile development slow and difficult to learn hands-on without a lot of guesswork, headaches and patience. Above all, things just move slower. 

The React Native Playground breaks down barriers to mobile development by making it speedy and trivial to write and test React Native code across platforms and devices. I want to share my experience working with an amazing team on this free resource. 

First, I'll give a quick tour of what's possible with the Playground, showing off some of React Native itself. 

We’ll see how React Native’s unique architecture made this project possible, revealing some interesting details of its inner workings. For example, how we're serving React Native javascript code over the web, and how we can load an application from inside another one. 

Finally, I want to briefly discuss how working on project like this, which help developers learn faster, can be fun, rewarding and an antidote to programmer fatigue.

Work and play in React Native Playground

React's future is going to be more functional, and less OOP. What if that future is already reality? How would it look like? React's foundations are reactive rendering and UI as a pure function of state. These two foundations are reactive programming and functional programming, yet React has a lot of concepts from imperative programming. In this talk we will discover how Cycle.js is purely reactive and functional, and why it's an interesting alternative to React.

Cycle.js and functional reactive user interfaces

This talk covers the evolution of Atom's view system, from its humble beginnings through the transition to React and then away from it again, and the landscape of possibilities for the future of Atom, or any large Javascript app targeting today's web platform.

ReactiveConf 2015

Nov 2 - Nov 4 | Bratislava, Slovakia