Cass has a professional theatre career spanning many years. His period in the UK included 7 years at the Royal National Theatre, many West End productions and freelance projects in Russia, Japan, Europe and the USA. In 1994 Cass joined the Sydney office of Cameron Mackintosh and was responsible for the Australian productions of Miss Saigon and Rent in addition to the Australasian, Asian and South African tours of The Phantom of the Opera and Les Misérables. Since 1999 Cass has been responsible for the original Australian productions of MAMMA MIA!, We Will Rock You!, Miss Saigon (2008 Tour), Billy Elliot the Musical and Moonshadow. International work has included supervising productions throughout Asia, South Africa and South America, along with the Korean language productions of MAMMA MIA!, Miss Saigon, Billy Elliot the Musical and Ghost the Musical. Recent projects undertaken include the Australian tours of War Horse, Agatha Christie’s The Mousetrap and A Murder is Announced, Dirty Dancing, Matilda the Musical, Fawlty Towers and MAMMA MIA! (20th Anniversary Tour).