BeatleTech is my (Coen Stevens) freelance company through which I offer my services, skills and experience in developing web applications and solving technical challenges.

Software Development

As an entrepreneur, scientist and hacker, who returned from silicon valley to pick the dutch weather over the San Francisco sunny days, I'm now looking for interesting job opportunities and challenges to help out your (startup) company, for which I'm available for freelance work.

Next to all-round web-development in Node.js, Clojure and Ruby, I'm specialized in:


Besides development I can also give advice on development and business strategies. As a founder of a Y Combinator startup I had my fair share of the emotional rollercoaster that every entrepreneur goes through, which I love to share and teach others my lessons learned.


I have worked on a host of applications with different technologies and frameworks of which the most notable ones I have listed below.

At Wakoopa I have desiged, optimized and extended their recommender system in Ruby, JRuby and Clojure, and additionally worked in Ruby on Rails on software classification, version number recognition and dashboard tools. At Newcope I continued working on building dashboard analytics using Ruby on Rails.

Next to Ruby on Rails I have a lot of experience in Javascript (JQuery), and server-side javascript called Node.js. For Newcope I build a fully fledged penny auction system, which was a perfect fit for Node.js's asynchonous nature.

Clojure is where I spend most my time both hacking in my free time on pet projects and for my previous work at GlobalOrange on data warehouse solutions and data import parsers.

In my early years I have worked a lot with Java, where one of my biggest projects was building an hours registration application. Nowadays I use a lot of java libraries in combination with Clojure, and use many of the Apache foundation projects (e.g. ActiveMQ, Solr, Maven, etc.)

At my previous job as IT architect I also designed and troubleshooted PHP applications, for which we already started using the Symfony 2.0 framework that is due for a final production release in March 2011.