I'm a full-stack software engineer from Voerendaal, the Netherlands. I started working as a freelance software engineer and scrum master under the company name cofx in 2022: https://cofx.nl. I'm not afraid of picking up any language or technology, but most of my experience is with Java, Clojure, and React-based front ends.

I wrote some blog posts for Kabisa, one of my previous employers, which are available on their tech blog. Hopefully, I'll pick up blogging again in the near future. Visit blog.cofx.nl to see whether we've already reached the near future.

I'll use this personal README.md as an introduction to my most noteworthy open source work. This is GitHub, after all.

Clojure for beginners is collection of assignments that should help you to get to know Clojure and ClojureScript. It is still a work in progress.

• Repo: https://github.com/ljpengelen/clojure-for-beginners
• On-line version: https://cfb.cofx.nl/

I created a Leiningen plugin and a hook for shadow-cljs that actually do the same thing: adding a hash to the filename of JS and CSS files before including them in index.html.

• Leiningen plugin: https://github.com/ljpengelen/lein-hash-assets
• Shadow-cljs hook: https://github.com/ljpengelen/shadow-cljs-hash-assets-hook

Top 10 is a musical quiz where the participants have to guess who is who based on their taste in music. The front end is a re-frame app written in ClojureScript. The back end uses Vert.x for Java.

• Repo: https://github.com/ljpengelen/top10
• On-line version: https://top10.cofx.nl

Lijstje is a small app for creating and sharing wish lists. It's available in Dutch only at the moment. There were already a lot of apps with similar functionality before I started working on this one. I couldn't shake the thought that there should be one more. Now, exactly the right number of wish list apps exist.

• Repo: https://github.com/ljpengelen/lijstje
• On-line version: https://lijstje.cofx.nl

Many projects that I worked on had the requirement that each commit message should contain a reference to a JIRA-ticket. Because typing those JIRA identifiers over and over again is no fun, I wrote a small script that takes the JIRA identifier from the name of the current branch.

• Repo: https://github.com/ljpengelen/prefix-commit-message
• NPM package: https://www.npmjs.com/package/prefix-commit-message?activeTab=readme

For Kabisa, I created a Cordova plugin for Signify's indoor positioning SDK.

• Repo: https://github.com/kabisa/indoor-positioning-cordova-plugin

I wrote a blogpost about creating good looking PDF with Markdown and CSS after I stumbled upon the excelent WeasyPrint by coincidence. The blogpost comes with a Python script that shows how this would work in practice.

• Repo: https://blog.cofx.nl/pdfs-from-markdown-and-css.html

• https://github.com/borkdude/quickblog
• https://github.com/cryogen-project/cryogen-docs
• https://github.com/tggreene/integrant-repl-autoreload
• https://github.com/cryogen-project/cryogen
• https://github.com/dpa99c/cordova-plugin-firebasex
• https://github.com/NimaSoroush/differencify
• https://github.com/mimischi/dokku-dockerfile
• https://github.com/kabisa/maji-extras