About Me

Freelancer located in Frankfurt (Germany).

Excellent skills in functional and object oriented software development using Clojure, Go Lang, Java and Java EE.

Architecture experience in designing horizontal scalable, reliable and high available system.

Broad coaching experience introducing test automation, continuous delivery, clean code and zero bug policy.


I work as software developer and coach for more than 10 years. I published a German book on Hibernate,
and an ebook on Java Persistence.

In parallel to projects, I have given dozens of trainings on Java Persistence, Java EE and Clojure in
places like Munich, Zurich, Paris, Dublin, St. Florian (Austria), Hannover and Stuttgart.

I publish detailed reviews of new technologies, participate and speak on conferences.

This broad knowledge helps me picking up roles as software developer or coach in projects.

Latest Projects

Coach and Lead Developer

Transportation business (2017 – now)

Coaching of three development teams. Continuing work on technical excellents. Introduction of micro services. Improving test skills in frontend area (unit and end-to-end).


VueJS, Cypress, Jest, Clojure, Go Lang, Spring Framework, PostgreSQL, MongoDB, Tomcat, Git, Jenkins, Junit, Mockito

Coach and Lead Developer

Transportation business (Oct. 2014 – 2016)

Training of a development team into REST based architecture with AngularJS as GUI technology. Introducing test automation, test driven development and continuous integration. Support in building a horizontal scalable architecture with NoSQL database.


AngularJS, Jasmin, Karma, Spring Framework, MongoDB, Tomcat, Git, Jenkins, Gradle, Grunt, Junit, Mockito

Architect and Coach

Stock exchange (2012 – Sept. 2014)

Training of 3 development teams into Java EE technologies, design pattern and unit testing.
Introducing current software development methodologies like test automation, test driven development and continuous integration.

As co-architect designing and establishing a scalable and highly reliable JavaEE based architecture. Training of development teams
into resilient design and participate in implementation.

Continuous work with 3 development teams: code reviews, continuous refactoring to keep code quality on a high level.
Introducing Agile Software Development, Agile Coaching


Java, Jboss, Java EE, JPA, REST Web services, Tapestry, JGroups Reliable Messaging, JBoss Cluster, AMQP Message Broker, PostgreSQL, Junit, Jmock, Python Nosetests, Maven, Jenkins, Git

Clojure Software Developer

Nature organization (2013 – 3 months)

Development of a backoffice application, Full-text search integration with Elastic Search


Clojure, Elastic Search, Lucene, AngularJS, Grunt, Jasmin, Karma, JavaScript, PostgreSQL, Jetty, CouchDB, Git

Architect and Senior Software Developer

Container logistic (2011 – 12 months)

Fireworker to get a project in a difficult situation into production, Rework of architecture, refactoring of application core, Integration of Spring Security, performance tuning, Migration of Spring XML to annotation configuration, Development of new functionality


Java, Spring, Eclipse RCP, Tomcat, Sybase DB, Subversion

GWT Development

Banking (2010 – 10 months)

Development of a GWT application to visualize customer relation, Multiple GWT components to integrate SVG libraries GWT components to integrate existing JavaScript diagram libraries Visualisation on mobile devices (IPhone, IPad)


GWT 2, GXT, SVG, Canvas, HTML 5, JavaScript, CSS

Publications / Conference Presentations

Presentation: Introduction to Clojure

(Devoxx 2014, Antwerpen)

A BOF session explaining all required tools and libraries to get started in Clojure development.

eBook: Java Persistence Developer Guide

(2006 – 2012)

A continuously updated ebook on Java Persistence.

Presentation: Selecting Web Technologies

(Devoxx 2009, Antwerpen)

A BOF session providing the audiance with a guidance how to select web technologies and explains pros and cons of different approaches.

Book: Hibernate Praxisbuch

(Paper book in German, 2007)

A book on Hibernate published by Galileo Computing, a well known German publisher.