He helped the side win three consecutive championships, though his time there was somewhat marred by an assault in a nightclub in 2009, in which he was injured and teammate Marian Cozma was stabbed to death.

He subsequently played for fellow German team Frisch Auf Göppingen from 2014 to 2018, winning two successive EHF Cup titles (2016 and 2017).

At youth level, Šešum was an instrumental member of the Serbia and Montenegro winning squad at the European Under-18 Championship in August 2004.

[4] A Serbia international since its inception,[5] Šešum made his major debut for the national team at the 2009 World Championship.

He was also a member of the squad that won the silver medal at the 2012 European Championship, but missed the final due to injury.