Photo My name is Hubert Klein Ikkink, but I am also known as mrhaki. I am born in 1973 and live in Tilburg, The Netherlands, with my beautiful wife and three gorgeous children.
I studied Information Systems and Management at the Tilburg University. After finishing my study I started to work at a company specialized in knowledge based software. There I started writing my first Java software (yes, an applet!) in 1996. During the years my focus switched from applets, to servlets, to Java Enterprise Edition, to Spring based software.
In 2008 I wanted to have fun again when writing software. The larger projects I was working on were more about writing configuration XML files, tuning performance and less about real development in my eyes. So I started to look around and noticed Groovy as a very good language to learn about. I could still use existing Java code and libraries and can use my Groovy classes in Java. The learning curve isn’t steep and to support my learning phase I wrote down interesting Groovy facts in my blog with the title Groovy Goodness. I post small articles with a lot of code samples to understand how to use Groovy. And since November 2011 I am also a DZone Most Valuable Blogger (MVB), where DZone also posts my blog items on their site.

DZone Most Value Blogger button


I have written three books about Gradle that are published by Packt Publishing. I also bundled a lot of my bloc posts into books published at Leanpub. Checkout the Books page for more information.

I also published several articles in Java Magazine which is a quarterly magazine published by the dutch Java user group NLJUG.


In 2010, 2011, 2012, 2013, 2014 and 2016 I was invited to speak at Gr8Conf in Copenhagen, Denmark. And in 2014 and 2015 also at Gr8Conf US in Minneapolis, USA. This is very good conference with all project leaders of Groovy and Groovy-related projects. So it was a great honor to be invited and to speak at the conference about my Groovy Goodness posts. You can see a Youtube video about Grails Goodness and Groovy Goodness I presented at Gr8Conf 2013 and Gradle Goodness at Gr8Conf 2014.
In April 2015 I presented a Grails Goodness talk at Greach. Greach is a very good conference with a good atmosphere.
In November 2010 I presented a Gradle talk at the J-Fall conference of the Dutch Java User Group. And in November 2011 I presented about the new features in Groovy 1.8 at the same conference. During the 2013 edition I presented a hands-on Gradle workshop. In 2014 I gave a talk about how awesome Asciidoctor is, and in 2015 a talk about how to write applications with Ratpack. During the 2017 edition I did a talk about Micronaut. The conference is visited by 1000 Java developers and I got the chance to educate some of them about the greatness of Gradle and Groovy.
In 2016 I spoke about Asciidoctor at Javaland in Germany and in 2018 about Micronaut.
I spoke also at several meetups and local meetings about various subjects concerning Groovy, Gradle, Grails, Ratpack and Asciidoctor.


JDriven I work at the great IT company JDriven. Here I work on projects with Groovy & Grails, Gradle and Spring. At JDriven we focus on agile, enterpris technologies. All colleagues want to learn new technologies, support craftmanship and are very eager to learn. This is truly a great environment to work in.