web and mobile applications from A to Z

I'm Luc Engelen, a freelance, full-stack software engineer and scrum master. I've been working independently under the company name cofx since 2022. Before that, I worked as a software engineer at various companies, either as an employee or a consultant. Before that, I worked as a researcher in academia. Over the years, I've spent a large amount of time thinking about software, writing about software, and creating software. I like to think that the quality of my work reflects this.

My goal as a software engineer is tackling complex problems in the simplest way possible. As software grows, maintaining and extending it becomes harder and harder; the larger an application becomes, the harder it gets to fully understand it. In my experience, keeping things as simple as possible is key to keeping software understandable in the long term, which in turns keeps it maintainable and extensible.

I'm satisfied with my work if it achieves its goal, no more, no less, and does this in a straightforward and obvious way. But don't be fooled, keeping things simple, straightforward, and obvious is hard work. I practise every day.


Software is just a means to an end. The chosen technology stack will not determine the success or failure of an application. However, sharp tools make good work. I prefer working with the tools below. They are pretty sharp if you ask me.

Front end

  • Languages: ClojureScript, JavaScript, and TypeScript
  • Frameworks and libraries: Reagent, re-frame, React, and Redux

I have professional experience with Angular and NgRx too, but prefer working with the tools above.

Back end

  • Languages: Clojure and Java
  • Frameworks and libraries: Spring Boot, Vert.x, Ring, Reitit, and Integrant

I've worked with Python and Ruby as well, but I have mixed feelings about Django and Rails. If you're looking for a passionate Python or Ruby developer, I'm not your best option.


  • Infrastructure as code: Terraform and Ansible
  • Cloud providers: AWS and Linode
  • Containerization: Docker and Dokku
  • CI/CD: Jenkins


Although I have created native Android and iOS apps, most of my experience with developing mobile apps comes from working with Apache Cordava.

For future projects, I'm keeping an eye on Flutter and ClojureDart.


Are you looking for an experienced full-stack software developer and scrum master? Someone to help out an existing team? Someone that can build and deploy a brand new application from start to finish? Feel free to get in touch!

I'm almost fully booked for the rest of 2023. However, if you're looking for someone for a small project that would take only a few hours every week, I'm open to discuss opportunities.

Phone: +31 6 1987 49 28
KVK number: 87652447
VAT number: NL004467493B09