Christian has pursued a successful career as a freelance Java software developer since 1997 and expanded it in 2005 to include the focus on IT security. His major areas of work are penetration testing and security architecture consulting. As a trainer, Christian regularly conducts inhouse training courses on topics like web application security and coaches agile projects to include security as part of their process by applying security DevOps concepts. Also, Christian regularly enjoys speaking on national and international conferences about IT security topics.