July 13, 18:45 @ Mobile World Centre

Join Us!


Keith Woods

Building Complex SPAs with React and ESP

What does it take to build a complex single page application (SPA)? How do you model state in a way that can be reasoned with yet scales with functionality and remains maintainable? How do you separate your view code from your state and update state in a deterministic manor? We'll answer these questions using a real world open source sample application, Reactive Trader, build on React and Evented State Processor (esp-js).

Language: en

Alex Saladrigas

Recording Audio/Video streams in the browser with MediaRecorder

Mozilla, Google and other browser makers are hard at work standardizing new Web APIs that will extend the abilities of the web. One such API is the MediaRecorder which will allow Javascript to very easily record media streams such as video or audio from different sources and save them or potentially manipulate them using other web APIs.

On this talk I will explain the current version of the MediaRecorder and provide examples of code snippets that can be used to capture and encode audio and video from the browser. Depending on the time constrains it might also be possible to include pointers for manipulating the data from the streams using something like Web Audio API.

I will give this talk as a Mozilla volunteer in the Tech Speakers program.

Language: en

For Everyone

We think coding is awesome and everyone should feel welcome at our event. This includes that we are expecting all participants to be awesome to each other and respect the Code of Conduct.

Open Source

Open source is the heart of BarcelonaJS. All our events, our website and our software are open source and can be modified by everyone.

Non Profit

BarcelonaJS is a registered non-profit association in Spain and is subject to Spanish law. All our events are not-for-profit and run by volunteers.


Front-end Jedi @ marfeel

Be part of Marfeel, one of the hottest European start-up companies. We are recommended at the very top by Google itself for our mobile design solution and with our partners we have over 2 billion worldwide readers and over 10 billion page views. Our headquarters are based in sunny Barcelona and our office has a huge terrace to enjoy. View Listing

Full Stack Developer @ Dreamstar Cash S.L.

We are looking for a Full Stack developer to join our team, the person will deliver Javascript development skills on the front and backend systems that power our site. The person is expected to have good knowledge of HTML and CSS, and the ability to work with our designers and the business to implement the features required. View on LinkedIn

Frontend Engineer @ Wallapop

Wallapop está buscando a un Frontend para incorporar a su equipo. Trabajará en el desarrollo de nuestro website y en el Backoffice interno y website junto con los equipos de Producto, Diseño y QA. La persona seleccionada será incluida desde el diseño a la concepción del producto, por lo que se requiere:

  • - Dos años de experiencia en proyectos Javascript.
  • - Capacidad de trabajar en equipos multifuncionales.
  • - Conocimientos de MVC/MVVM frameworks (AngularJS, Ember.JS...), ES6.
Apply Now

Submit a talk

work in progress :)


Come to BarcelonaJS

Join Us!


Previous Talks