José M. Pérez

José M. Pérez

Engineer at Facebook and GDE in Web Technologies. Ex Spotify.

Speaking at Alicante Frontend

This week I had a blast speaking at a meetup organised by Alicante Frontend. To me this was really special. Alicante is my home town and it’s also where I studied Computer Science.

Alicante Frontend

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Collaborative listening on Spotify using Connect endpoints

This is a post about a hack project I have been working on lately, and I wanted to share some information about why and how I built it.

tl;dr Here is the demo and the project on GitHub.

C, collaborative room to listen to Spotify

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Hiding the outline or :focus ring in an accessible way

Last week I came across Removing that ugly :focus ring (and keeping it too). It’s a really good post about outline, that CSS property lots of devs tend to hide. The post explains some a11y-friendly alternatives to not display it, and show it when needed.

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The (mobile) web is making a come-back

The web ecosystem is maturing and every day we understand better how to architecture large and maintainable web applications. We also understand what makes our sites slower and are coming up with solutions to overcome this.

Building a complex site that can work on slow networks is a challenge. One that some companies have decided to accept without fear and share with the developer community.

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Reading List

This is a list of some posts and talks I have read and watch during the last days. I write it to keep track of interesting content for myself, but you might also find it useful.

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PerformanceObserver and Paint Timing API

In a recent post about Chrome 60 Beta, Google announced the support of the Paint Timing API to get metrics on when your page starts rendering and when the user gets content that can be consumed (more info on the definition of the events below). Here I’m going to describe this new API a bit and show you how to use it.

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Speaking at JSDayES 2017

I just attended JSDayES 2017 in Madrid, where I gave my talk about images and web performance. It feels great to be back to the same venue where I gave my first talk 4 years ago in SpainJS with Tomás Pérez, who also made it to the event.

I have caught up with lots of colleagues I used to work with in Tuenti, and lots of JS devs from the Spanish community. There is a lot going on in Madrid and the rest of Spain, with very interesting companies building awesome products.

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Playing with the Spotify Connect API

Spotify released recently a set of endpoints in beta to fetch information of what is playing and send playback commands. This allows for a wide range of integrations and I wanted to hack a bit with it.

Spotify Connect

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Speaking at Render Oxford 2017

I just attended Render 2017, where I gave a talk about images and web performance. It’s my first time in Oxford and I was impressed by its beauty. The organisation was great and I had a lot of fun.

The Render Conf 2017 sign by the entrance of King's Centre

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More examples of Progressive Image Loading

In a past post I dissected a technique used by Medium to display images, transitioning from a blurry image to the final one. Since then I have found some more sites following a similar approach. Let’s see how Quora, Quartz and Clicktorelease do it.

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