Hi there! My name is João Diogo Costa, I’m 23 and I live in Coimbra, Portugal.

I’m lucky enough to do what I love for a living: Software Development. I learned to program with Python, Java, and Matlab (I’m a science guy too!) and now I’m a very happy Ruby (mostly) and Javascript developer.

Jump to the TL;DR section if you don’t want to be bored to death. Seriously, I mean it.

I started to learn Web Development with Django but rapidly switched to Ruby on Rails, where I built up my experience in Ruby along with the standard web browsing technologies (HTTP, Javascript, CSS and HTML). I also have experience in working with relational and non-relation databases, mainly PostgreSQL and MongoDB (I also got my hands on Redis for other matters).

This is what I do at REDLIGHT, an awesome software consultancy company where I spent my days since June, 2014.


I’ve been exploring other technologies too. I’ve used Node.js in a couple of projects and also had some fun with Meteor, Sinatra and Padrino. Right now I’m in the process of finding the client side framework that best suit my way of thinking. AngularJS, React, Ember and Backbone.JS (the usual suspects) are the candidates. I guess they all have good parts and bad parts, and most importantly, have been made to fit different needs. I’m getting to the conclusion that I’ll just have to pick whichever is the best for each project.

Well, the last paragraph is actually obsolete. I already found the “framework” that suits my needs, or even better, the one that matches my way of thinking regarding client-side web applications: React. I use it everyday now, along with Redux and React-Router. It can be cumbersome to set them up together in the first place (yes, Webpack is very cool), but once you get it right, you will not want anything different.

My tendency for Web Development have been evolving to other fields as well. The ideia of machines communicating with each other, performing extremely complex processes involving data analysis and decision making without the intervention of a human just fascinates me. This lead me to dive in the world of Embedded Systems, REST APIs, Internet of Things and ultimately Service Oriented Architecture. This is what I’ve done while I was at Whitesmith, a software consultancy company based in Coimbra and London.

Although I’m not currently working with all these concepts on my day-to-day job, they definitely changed the way I think about Web Systems and their architecture.

Hey, seriously, jump to the TL;DR section or you’ll fall asleep.


I was very lucky to be part of a crazy group of college kids who ran a company. It is known as a Junior Enterprise but I think the term is kind of confusing and unappropriate. Jeknowledge is so much more, it’s a fertile place where people hacked everything. Seriously. Can you imagine a bunch of college kids running a company? We hacked culture, funding, finances, technology, community, events, … Everything needed to keep the clients happy and our people happy and motivated.

I learned so much in there. I got into web development, met a lot of people who are doing spectacular things in my city, learned how to manage a team, how to manage a project, how to manage a micro company and how to plan and organize events like 3 Day Startup and Shift Appens.

Shift APPens

If you study at Faculty of Sciences And Technology - University of Coimbra and you’re not part of jeKnowledge, please consider to at least pay a visit to these guys and see what they’re up to.

I owe what I am now to jeKnowledge.

You studied what!?

Did I mention I’m a Biomedical Engineer? Well, I studied Biomedical Engineering in the University Of Coimbra and I actually got a Master’s Degree on that.

But hey, don’t get me wrong because I don’t plan to be a lab rat. I’ll continue to be a very happy Software Developer. Maybe a very happy Software Developer with some knowledge in harcore Math, Physics, Microelectronics and Human Biology, but that’s all.


I love planes since I was a kid and I actually had the guts to follow my dream: to be a military pilot. I joined the Portuguese Air Force right after finishing High School, as a pilot candidate. I had the chance to pilot a beautiful aircraft, and no words can describe what I felt there.

The incredible feeling of flying an aircraft was not enough to tolerate the constraints of a military life. Nonetheless, the best seven hours of my life were spent there, 4000 feet above the ground.

Força Aérea

My ultimate goal is to go back to the 4000 feet in my own airplane.


  1. In 2009 I joined the Portuguese Air Force and left shortly after. In this year I also joined University Of Coimbra to study Biomedical Engineering.

  2. In 2011 I joined jeknowledge and my life as it was completely changed. I also had a short experience as a junior researcher at Group of Electronics and Instrumentation doing Computer Vision with Matlab and OpenCV.

  3. In 2012 I joined SARKKIS, a tech startup in the medical devices field. Here I did Image Processing, 3D printing, market research and business development. This year, we (jeKnowledge) organized the first 3 Day Startup in Portugal.

  4. In 2013/2014 I was a kind of “Chief Innovation Officer” at jeKnowledge. Together with NEI, we came up with a pretty cool Hackathon for college students - Shift Appens.

  5. In 2014 I joined Whitesmith to work with Internet of Things (sensors, APIs, web, eletronics). Still in 2014, I joined REDLIGHT to work with web technologies (Ruby on Rails, Javascript and friends).

  6. In 2015 I released my first Ruby gem - Season.

  7. Nowadays I spend my working time (and sometimes my free time as well) working with React, Redux and React-Router.