Calum began his career at the renowned Sarm Studios in West London, where he honed his skills as an assistant before advancing to a full-time role as Trevor Horn’s Engineer. During this time, Calum contributed to multiple top 10 records, including Rod Stewart’s UK #1 album "You’re In My Heart". After transitioning to freelance work, Calum’s reputation grew as a sought-after engineer, vocal producer, and mixer, earning him his second UK #1 album with Stormzy’s "This Is What I Mean" and a UK #2 album with Potter Payper’s "Real Back In Style".

In 2023, his extensive client list continued to expand, with notable collaborations including Kid Cudi, No Guidnce, RLY, Alison Goldfrapp, and Jeymes Samuel. Calum engineered and vocal arranged the soundtrack for Samuel’s Hollywood blockbuster “The Book of Clarence”, which featured a star-studded lineup of top artists from the worlds of pop, hip-hop, and R&B.

In 2024, Calum continued to build on his success. He mixed Will Clarke’s debut album, and mixed and engineered tracks for Debbie on 0207 Def Jam. Additionally, he received his first Grammy nomination for his engineering work on Tems' album "Born In The Wild", marking a significant achievement in his career.