In 2010, while he was studying at the Masaryk University, Karel Šimek began working as an assistant stagehand at the Mahen Theatre in Brno, where he became interested in light. He left his studies and intensely devoted himself to working with light. In 2012, he also began working for the Ha Theatre (HaDivadlo) in Brno. At the end of 2013, he moved to Prague where he was engaged as the Head of the Lighting Department at the Švanda Theatre (Švandovo divadlo) in Smíchov. He began working as a freelance lighting designer and technician for primarily alternative, non-verbal and physical theatre companies at the beginning of 2015. Up until that time, he had been working with such artists as Radim Vizváry, deKKadancers, the Spitfire Company, Tantehorse, MIME PRAGUE, Tichá opera, Lenka Vágnerová & Company, and the Voso5 Theatre company, as well as other independent companies and choreographers. These collaborations led to his engagements on projects with the Ballet of the National Theatre in Brno, the Prague Chamber Ballet, La Compagnie des Pieds Perchés, Matěj Matějka and others, which have been presented on stages all over the world. He has twice been a member of the “golden team” in the Backstage Battles - Theatre Technician Olympics.