Heggemsnes became a senior in 2017, making his international senior debut at the Varna World Cup in Bulgaria, placing seventh in the pommel horse final. He went on to compete at his first World Championships in Montreal, Canada, but did not make any finals. In 2018, he competed at the European Championships in Glasgow, and the World Championships in Doha, where he placed 40th all-around in qualifications, and 22nd with the Norwegian team. He also finished seventh on pommel horse at the 2018 Guimarães World Cup.