André B. Bondi is a senior staff engineer working in performance engineering at Siemens Corp., Corporate Technology in Princeton, New Jersey. He has worked on performance issues in several domains, including telecommunications, conveyor systems, finance systems, building surveillance, railways, and network management systems. Prior to joining Siemens, he held senior performance positions at two start-up companies. Before that, he spent more than ten years working on a variety of performance and operational issues at AT&T Labs and its predecessor, Bell Labs. He has taught courses in performance, simulation, operating systems principles, and computer architecture at the University of California, Santa Barbara. Dr. Bondi holds a Ph.D. in computer science from Purdue University, an M.Sc. in statistics from University College London, and a B.Sc. in mathematics from the University of Exeter.