About me

My name is Jan Ouwens and I’m a developer from the Netherlands. Currently, I work for Codestar. I do a bunch of things:

Projects

EqualsVerifier - [site] [github] [java]
A tool to make rigourously testing Java’s equals and hashCode methods a one-liner
Parallel Java - [github] [java]
A Todo Backend written in Java, without using annotations, to support my talk Java from a Parallel Universe
PicoTest - [github] [java]
An ultra-minimal unit-testing framework, based on the JUnit 5 Platform
Foobal - [site] [github] [scala]
A program I use to predict the outcome of soccer matches, so that I can participate in the family pool without needing to learn about the actual sport
ReminderMail - [site] [github] [kotlin]
A small Android app that makes it easy to quickly send mails to yourself
ComposeKey - [site] [github] [scala]
A bundle of text-expansion snippets for Alfred that mimic the behaviour of Linux’s compose key
vim-reversal - [github] [vimscript]
A colorscheme for Vim that highlights identifiers and de-emphasizes keywords, so you can easily see what’s important in your code

Java from a Parallel Universe - [link]
What Java would look like in a world where annotations were never invented.
Delivered at J-Spring 2019 and J-Fall 2019.
Don’t hack the platform? ☠️💣💥 - [link]
A funny anthology of tricks and hacks for the JVM.
Voted 2018’s “best non-Venkat talk” by the J-Fall audience!
Delivered at J-Fall 2018, JavaZone 2018, JBCNConf 2018 and more.
Not all equals methods are created equal - [link]
How to write a good equals method, and to test it with EqualsVerifier.
Delivered at Devoxx 2017.
Growing a DSL for financial calculations - [link]
The story of how my colleague and I ‘discovered’ a Scala DSL for writing complex mortgage calculations.
Delivered at Typelevel Summit Oslo 2016 and Codestar Launch Event.

2011 - present, tr ouwens - 🇬🇧 [site]
my tech blog
My publications in the Dutch Java Magazine
- September 2020, Actief worden in open source (met Danny van Bruggen)
- October 2018, Lees dit niet! ☠️💣💥 - 🇳🇱 [site]
- February 2018, Selenium is leuk met ScalaTest - 🇳🇱 [site]
- April 2016, Een DSL kweken - 🇳🇱 [site]
- June 2015, Grip op je buildproces met Gradle (met Hanno Embregts) - 🇳🇱 [site]
2009 - 2012, Brief en leed - 🇳🇱 [site]
a funny letter-writing blog I did with my friend Ralf
January 2008, Voorstel voor een methode voor de kwantitatieve analyse en vergelijking van beeldverhalen - 🇳🇱 [PDF]
a way too in-depth survey of Asterix jokes
August 2005, The Performance of Wireless MPEG-2 Video Streaming - 🇬🇧 [PDF]
my Master’s Thesis