Rosta initially appeared mainly on stage shortly after completing his training. He made his professional debut at the Hampstead Theatre in the production The Harmony Test.[2] During his training, he had also performed in plays such as Romeo and Juliet, The Cherry Orchard, and The Watsons.[1][3]
Rosta landed his first major screen role in the television series Star Trek: Starfleet Academy, which premiered on the streaming service Paramount+ in January 2026. In the series, he portrayed the human cadet Caleb Mir, a member of the newly re‑established Starfleet Academy.[4] Rosta was cast after being selected from over 400 candidates following a chemistry read with the co-star Holly Hunter, whose immediate connection with him convinced the showrunners of his authenticity.[5]
Previously, Rosta had taken part in the CA$5,000‑budgeted student project Snitches Get Stitches (2021), directed by Aaron Rubinoff, a thesis film created by students at the RTA School of Media at Ryerson University.[6]