After returning to Australia, Kassim attended St Hilda's Anglican School for Girls in Perth, Western Australia. She also studied abroad at New York City's Lee Strasberg Theatre and Film Institute. In 2008, she earned an Associate Diploma in Speech and Drama Performance from the Australian Music Examinations Board and in 2014 graduated from the University of Western Australia with a Bachelor of Arts & Literature.

Following her studies, Kassim relocated to Sydney to pursue a career in entertainment. While studying in her final year at university, she entered the Miss World Australia beauty pageant where she was named runner-up. In the same year, she was cast in three Australian independent feature films as well as a role in the SBS TV series Legally Brown and the Discovery Channel documentary series Deadly Women, all of which were released in 2014.

Kassim’s breakout role in Australia came when she was cast in the recurring role of Shay Daeng on the Australian soap opera television series Neighbours. Following Neighbours, Kassim moved to Los Angeles and began auditioning for feature films where she was successful in landing roles in two upcoming productions. She is set to appear in the role as Kina in Jungle, directed by Greg McLean and starring Daniel Radcliffe, and Lisa in Nest starring Kelsey Grammer.