Firus attended Sentinel Secondary School in West Vancouver. After part-time business administration studies at Capilano University, Firus became a student at Athabasca University, pursuing a Bachelor of Commerce degree with a major in finance.
He is a three-time Canadian national medalist (silver in 2016, bronze in 2014-2015). Firus started skating as a hockey player in 1999 and eventually switched to figure skating. Lorna Bauer began teaching him when he was eight years old.
In the 2010-2011 season, Firus finished 6th in his senior national debut at the 2011 Canadian Championships and was assigned to the World Junior Championships where he finished 20th.
Firus began the 2011-2012 season by winning the bronze medal at the Junior Grand Prix event in Brisbane, Australia. In the 2012-2013 season, Firus experienced severe pelvic pain while training for the Canadian Championships.
He placed fifth at the event in January 2013. His condition developed into osteitis pubis and he decided to undergo prolotherapy.
He resumed training after five months.
In autumn 2013, Firus began training under Christy Krall in Colorado Springs, Colorado. He finished 28th in Sochi. He finished 15th at the 2015 Four Continents Championships.
He withdrew from the 2016 World Championships in Boston, stating "Making this decision was extremely difficult.
However, I feel that withdrawing from the World Championships is vital for our team".
A member of the North Shore"s Vancouver Skating Club, he trained in the fall and winter at the Pacific National Exhibition Agrodome and the rest of the year at the Canlan Ice Sports Arena.