Steffen studied physics at the RWTH Aachen, the EPF Lausanne, and the University of Heidelberg. He did his diploma and PhD theses in the Light Microscopy Group at the European Molecular Biology Laboratory (EMBL), Heidelberg, where he developed novel high-resolution light-microscopy techniques, for which several patents were granted. From 1996 to 1999, he was a post-doctoral fellow with the BioImage project at EMBL and worked on the design and the implementation of the BioImage database for microscopy images.
Since 2000, Steffen has been working as a freelance scientific database and metadata consultant for various academic and commercial clients, mostly in the UK and in Germany. During this time, he acquired extensive experience as a project manager for international scientific research initiatives.
One of Steffen's foci is the field of the Digital Object Identifier (DOI), and he worked as a consultant for the International DOI Foundation and for several of its members. In particular, he was involved in projects based on the <indecs> framework such as the MPEG-21 RDD project and in building ontologies to support XML messaging standards such as DDEX and ONIX. Currently, he is working on data modeling, COA design and ontology development for Ontologyx, Rightscom’s proprietary ontology based on an innovative contextual semantic structure.