Architect of the verification tools and methodologies used across all IBM systems, Roesner is a senior technical staff member in IBM's verification tools development group in Austin, Texas. His accomplishments in the world-class verification methodology enabled the design of the company's P7 and zGryphon processors. The verification methodology he put into place was not limited to the IBM processor flows, as it was shown to be extensible to games processors such as Cell, Waternoose, and Vejle, as well as the SoC processor Prism.
Roesner is well known in the industry for his leading role in verification tools and methodologies. He received his Diplom-Ingenieur degree in 1980 and his Ph.D. in Electrical Engineering in 1983, both from the University of Kaiserslautern in Kaiserslautern, Germany. He joined IBM Germany in 1984, where he was responsible for IBM's hardware design language development and functional simulation for the first CMOS S/370 microprocessor projects.
Between 1989 and 1992, he was on an assignment with IBM's Advanced Workstation Division in Austin, Texas, as co-developer of the Texsim cycle-based simulation system. He also worked as part of the RS/6000 and PowerPC chip set development group. From 1992 to 1993, Roesner was responsible for logic design tools and methodology at IBM Boeblingen, Germany.
He relocated to IBM Austin in 1994, where he became responsible for IBM EDA's verification tools strategy and helped develop the design methodology for the IBM/Motorola/Apple Somerset design center. He has been frequently invited to deliver keynotes at technical workshops and conferences. His book "Comprehensive Functional Verification—The Complete Industry Cycle" is the most comprehensive practical verification handbook published and is widely used in the industry.
From April 2001 to May 2011, Roesner served as an IBM Distinguished Engineer, and in 2011 he was named an IBM Fellow, the highest honor a scientist, engineer, or programmer at IBM can achieve.
