François Koessler

Freelance full stack web engineer

Ruby on Rails addict, Javascript enthusiast, Drupal lover.

Hi, I'm François Koessler, an independant web developer located in Strasbourg, France.

I do subcontractor work with web agencies or startups and help them with site building, integration and development. I also work with private individuals if they have a precise project in mind I have an interest in. Every project has its specificities and I will recommend the best technology to optimize development costs, performance and security.

I think that communication is the key for a successful web project, that's why I make my work visible as soon as development starts and require regular feedback from my clients.

CMS development / Integration

I do website integration with Drupal or Wordpress. I master both of those CMS in their entirety: site-building, theming, development, deployment, performance and security.

Example work: Huayang Language Academy

Responsive design.
Easy to manage content.
SEO optimized, fast and secure.
Check it out

Huayang Language Academy website screenshot

Web Development

I design web applications' architecture and implement them following the Agile development methodologies.

Technologies I work with:
  • Ruby on Rails / PHP Symfony2
  • Javascript - Angular.js / jQuery
  • MariaSQL, MySQL, PostgreSQL

Example work: The Poet


The poet is a prototype web application that can programmatically compose a personalized poem based on your answer to five questions.

The poet prototype is built with Rails4 and Angular.js.

Unit tests implemented with RSpec and FactoryGirl. Integration tests written with capybara.

Check it out

Other works

Out of all the different web-developers I have worked with in the past, I particularly enjoyed working with Francois. He is reliable, responsive, capable and simply a good web-developer. I will keep calling on him for all our website issues and highly recommend him!

Huihan Lie,

Will I ever find a better developer/programmer than Franz Koessler? It is hard to imagine. We have worked together for almost two years now. I could go on and on about the great job he had done as my partner in developing He is honest, diligent, reliable, creative, efficient, organized, self-motivating, personable and great at learning new things. He has been also very good at estimating his time and when he would be able to provide delivery…something many developers are quite poor at. Whoever has the good fortune to contract with him in the future will be very lucky to have found him.

Dwight Goldwinde,
  • Mobile: (+33)0656772865
  • Skype: