Between 1997 and 1999 he played Theo Klages in German soap opera Lindenstraße, who wed Carsten Flöter before same sex marriage was made legal.
In 1997, Ullman completed a synagogue memorial in collaboration with Zvi Hecker and Eyal Weizmann, commemorating the former Lindenstraße synagogue in Kreuzberg.
He has previously worked in television productions such as Sechserpack, SOKO Köln and Lindenstraße.