Making her international debut, Byun placed 15th at the 2012–13 Junior Grand Prix (JGP) event in Lake Placid, New York.

After placing 14th at the 2014 South Korean Championships, Byun competed at her first senior international, the 2014 Triglav Trophy, where she ranked 5th.

[2] In the 2014–15 season, she placed 10th competing as a senior at the Lombardia Trophy, an ISU Challenger Series event held in Milan.

In November, she was awarded her first senior international medal – bronze at the 2015 Volvo Open Cup, after placing second in the short program and fourth in the free skate.

[4] She finished 10th at the 2016 South Korean Championships and was selected to compete at the 2016 Winter Youth Olympics in Hamar, Norway.