Mathias has been a social scientist, consultant and journalist since 1994 within European strategies and programmes, comprising a wide range of policies such as building, housing, regional and urban development, economic promotion, employment, education, migration and social integration. 

He was and is involved in many transnational exchange activities funded by the EU and the OECD such as ESF Innovative Actions, EQUAL, ESF Learning Networks, INTERREG, LEED Forum on Partnerships, URBAN and URBACT. 

When his hometown Hamburg applied as host of the Olympic and Paralympic Games for 2024, he started his work on mega events and urban development including Hafen City Hamburg.