Before joining Birkbeck College as a lecturer he worked as the Research and Development Manager for a multinational information technology corporation in Athens, Greece, where he was responsible for the strategic development of new IT products in the areas of knowledge management and the mobile internet; asthen Internet Systems Security Officer for the Ministry of Defence, Athens, where he designed the Hellenic armed forces Internet exchange and domain name systems; and as a research fellow for Imperial College, London, where he conducted research in distributed systems. He is currently investigating the effects of social activity on system architectures, and exploring mechanisms to support navigation and findability. He is a member of the ACM, SIGMOBILE, the IEEE, the IEEE Communications and the IEEE Computer Society.