Since r. 1980 until now he has been working as a university teacher at the Faculty of Mathematics, Physics and Informatics of Comenius University in Bratislava. He specializes in image processing and computer vision. He works at the Department of Applied Informatics, FMFI UK. From 1990 to 2002 he served as a member of the National Council of the Slovak Republic, in 1998-2002 as Minister of Education. In 2006-2010 he was the mayor of Bratislava-Petržalka and in 2010-2014 mayor of Bratislava. He was also a member of the municipal and regional councils. Since 2015 he has been the Chairman of the Slovak Information Society and a member of the Presidency of the Council of European Information Society. He is also a member of the Government Council for Digitization of Public Administration and the Digital Single Market. Since January 2019 he has been the Chairman of the Smart Solutions and Innovation Council, which is the coordination platform of the Smart cities club and the Slovak smart city cluster.