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Contributor Spotlight

Ulli Hafner

Munich, Bavaria, Germany
First Commit: 2007
Date Published: 2024-01-23

Ulli Hafner is a professor of Software Engineering at the University of Applied Sciences Munich where he advocates for Jenkins in several ways. He is also a software developer, open-source contributor, plugin maintainer, and serves on the Jenkins governance board.

He is also part of the UX SIG, participating in meetings and providing various UX contributions over the years. Ulli enjoys helping new contributors grapple with Jenkins and giving talks at Jenkins events, where he can offer his insight into open source. In his free time, Ulli likes to balance his screen-usage by spending time with his family, being outdoors, and being active through sports or swimming.

What is your background prior to contributing to Jenkins and outside of Jenkins?

I was a software developer and architect, and had never contributed to open source before Jenkins.

Currently, I am the maintainer of several Jenkins plugins, mostly in the area of build result visualization using modern JS based user interfaces. For example, I am the maintainer of the Warnings, Coverage, and Git Forensics plugins, as well as several UI related JS wrapper plugins like Bootstrap, Prism API, or ECharts. I am a member of the Jenkins UX SIG and the Jenkins Governance Board.

During the day, I am a professor of Software Engineering at the University of Applied Sciences Munich, where I also try to win new Jenkins contributors by letting students develop new features in their student projects and theses. I am also helping new contributors and students in our Jenkins forums or by giving some talks at our Jenkins Meetups.

I am a father of two children, and try to spend time with my family as much as possible. As a balance to a job that requires a lot of time in front of a computer, I partake in a lot of sports such as basketball and swimming. I am a lifeguard and swimming trainer for children in our junior lifeguard group.

How long have you been using Jenkins?

I have been using Jenkins and contributing to Jenkins for more than 15 years now.

Why choose Jenkins over other projects?

I needed Jenkins in one of my company projects. I was the architect in the team, and one of my responsibilities was to make sure that we deliver only high-quality code.

What problems has Jenkins solved for you?

Jenkins helped me ensure that a lot of quality gates, that the team defined in the "Definition of Done", could be automatically checked and reported in a rich user interface.

Is there an aspect of Jenkins that you’re particularly passionate about?

It is all about the user interface. I like to improve the user experience and the look and feel. So, in particular, how can we best represent the various results of quality assurance tools such as testing, coverage, and static analysis in Jenkins' user interface.

What sort of contributions have felt the most successful or impactful?

I think the most impactful contributions are the plugins for static analysis and code coverage, in combination with the git forensics plugin. Both plugins have a user base of more than 25,000 installations. The static analysis plugins won the first prize of the SUN Open Source Community Innovation Awards Program in 2008.

Advice for new developers and new members of the open-source community

Do not reinvent the wheel; maintain or improve the quality standards of the existing projects.