He joined Carnegie Mellon in 2012, after a two-year postdoc in the group of Klaus Ostermann at the University of Marburg. He received his Ph.D. from the University of Magdeburg in 2010 for his work on virtual separation of concerns. For his dissertation he received the prestigious GI Dissertation Award for the best computer-science dissertation in 2010. His research focuses on quality assurance for highly-configurable systems and in understanding and managing variability-induced complexity. He combines programming-language research and software-engineering research in the areas of software product lines, feature-oriented programming, modularity, metaprogramming, software analysis, program comprehension, empirical studies of developers and development artifacts, and program transformations.