He served as technical leader of the FAMOOS Esprit project, a project whose goal was to propose a set of reengineering techniques and tools to support the development of object-oriented frameworks. He is an expert in object-oriented programming, design patterns, framework development, reflective programming and component technology. He is one of the main designers of the MOOSE reengineering environment that is the basis for CodeCrawler, a program understanding tool. He is the main organizer of the annual European Smalltalk Advanced Seminars.