He has delivered numerous scalable, elegant solutions for companies ranging from non-profits to military subcontractors; he has also been a featured contributor in the developerWorks community. He currently works and resides in the DC area.As current maintainer of Sinatra, Konstantin is an Open Source developer by heart. Ruby has become his language of choice since 2005. He actively participates in the Ruby community and regularly contributes to different widespread projects, like Rubinius and Rack. In 2010, he successfully took part in the Ruby Summer Of Code, working on Rails internals. Haase is currently studying IT Systems Engineering at the Hasso Plattner Institute in Potsdam, Germany, and works part time as a software engineer at finnlabs in Berlin.