Upon completing her studies, Ritmanis began working at Warner Bros. and Walt Disney Studios, which led to work in the field of orchestration for film and television. She was able to secure a steady supply of work from composers such as Michael Kamen, Basil Poledouris, Shirley Walker, Mark Snow, Paul Chihara, Bennett Salvay, Elliot Goldenthal, Louis Febre, Burt Bacharach, Snuffy Walden, and Carter Burwell. In 1991, with the help of composer Shirley Walker, Ritmanis began her career as a film and television composer. Her collaboration with Ms. Walker provided an opportunity for her to write music for Batman: The Animated Series at Warner Bros. Studios. She continued at Warner Bros. with work on Superman: The Animated Series and Batman Beyond. During this period of time, Ritmanis met and began a professional collaboration with composers Michael McCuistion and Kristopher Carter. The trio went on to compose music for The Zeta Project, Teen Titans, Justice League, Justice League Unlimited, Legion of Super Heroes, and several long-form projects.
