Mazurchuk started his international career when he competed at the 2015 European Youth Olympic Winter Festival in Tschagguns, Austria, where he was 29th in the NH/10 km competition. At the beginning of his sporting career, Mazurchuk also competed in ski jumping, but those were only FIS Cup competitions. He last started as a ski jumper in September 2018.
Mazurchuk debuted at the World Cup on January 13, 2018, in Italian Val di Fiemme where he was 16th in men's team sprint (together with Pasichnyk). His first individual World Cup race took place on November 30, 2018, in Norwegian Lillehammer, where he was 55th. As of January 2023, Mazurchuk's best individual World Cup result was 30th on January 9, 2022, in Val di Fiemme, Italy.[5] His best personal Continental Cup result remains 8th rank from December 4, 2021, in Chinese Zhangjiakou.
In 2022, Mazurchuk was nominated for his first Winter Games in Beijing.[6] He participated at both individual events. His best finish was 32nd in the large hill/10 km competition.[7]