Daniel Bovensiepen Li


I'm a Senior Key Expert Research Scientist with Siemens. For the last 22+ years I have worked in the areas of communication, automation and manufacturing as an engineer, project manager and researcher. In these areas I hold several patents.


My hometown is Berlin. Yet since 2007 I spend most of my time in Beijing. I'm active in the Open Source community in general with a special focus on Ruby. I'm a contributor to several OSS projects, a public speaker and an author.


Some thoughts and remarks I write in my blog.

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Send a mail to daniel [at] bovensiepen [point] li

I'm also reachable via GitHub, Mastodon, Twitter and LinkedIn.


I spoke at several conferences:

2023RISC-V Summit China, Beijing, China
2023Open Source @ Siemens, Zug, Switzerlandvideo
2017RedDotRubyConf, Singaporevideo
2014RubyConf China, Beijing, China
2014eurucamp, Berlin, Germanyvideo
2013RubyConf China, Beijing, China
2013RubyKaigi, Tokyo, Japan
2012Ruby World Conference, Matsue, Japan
2010Ruby World Conference, Matsue, Japan
2010RubyKaigi, Tsukuba, Japan
2009RubyKaigi, Tokyo, Japan
2006EuRuKo, Munich, Germany


I was several times interviewed about my work. Here is a selection of some of the public ones:

  • Teahour
    A chinese technology Podcast where I talked about my work on mruby and it's usage to detect pollution in China.
  • Software Engineering Daily
    An american software Podcast where I talked about the security of mruby.

Articles and Books

In the past I was asked several times to write technical information (mainly about Ruby) on real paper. The results were published in magazines and books. I'm not actively looking for author projects. Nevertheless, if you have a project in mind of which you think it fits my expertise, get in contact with me.

"Ruby - Das Einsteigerseminar"

Book cover for Ruby Das Einsteigerseminar

In 2007 I wrote the german book "Ruby - Das Einsteigerseminar" (ISBN: 978-3826674594). This is a starter book for the Ruby programming language (version 1.8). It contained next to the introduction of the language itself an exercise area for each chapter and a project (photo management software) written from scratch in Ruby.

"Ruby die 1.9te"

RailsWay Magazin Cover for Ruby die 1.9te Article

Together with Florian Gilcher, I wrote in March 2009 the cover article "Ruby die 1.9te" for the german Ruby Magazin RailsWay. We covered the syntax changes since version 1.8, the regular expression machine called Oniguruma and introduced the new encoding system in detail.

"Wie das i vor den Ruby gelangt"

RailsWay Magazin Cover for iRuby Article

In May 2009 we (Markus Prinz and me) wrote the article "Wie das i vor den Rubin gelangt". This was also the cover article of the german Ruby Magazin RailsWay and covered the Ruby integration of MacRuby inside of Mac OS X. We illustrated the usage of MacRuby by programming a demo application to learn kanji on the Mac.

"Ruby Konferenzen"

RailsWay Magazin Cover for Ruby Conference Article

After my trip to Japan in July and September of 2009 I wrote two articles for the german Ruby magazin RailsWay about the RubyKaigi and RubyWorldConference.