He received his Ph.D. from Albert-Ludwigs-Universität Freiburg in 2006. His main research interests are in automated planning, heuristic search, and combinatorial search and optimization problems in general. He has received more than ten best paper awards or honorable mentions for such awards at major AI venues, including best paper awards at AAAI, ECAI and ICAPS and an honorable mention for the IJCAI-JAIR Best Paper Prize. In 2011, he was honored with the IJCAI Computers and Thought Award for fundamental contributions to the theory and practice in automated planning and combinatorial search. He was conference chair of ICAPS 2011 and SoCS 2013, is an associate editor of JAIR and a member of the ICAPS executive council.