Saarinen started skating when she was about five years old. She began competing on the junior international level in autumn 2012 and was assigned to the 2013 World Junior Championships in Milan, Italy, where she finished 14th.
Saarinen made her ISU Junior Grand Prix (JGP) debut and won the junior title at the 2014 Finnih Championships. She placed 13th at the 2014 World Junior Championships in Sofia, Bulgaria.
Saarinen continued competing on the JGP series before making her senior international debut at the 2014 Finlandia Trophy, aChallenger Series (CS) event. In November 2014, she won a bronze medal at the CS Volvo Open Cup. In the 2015 World Junior Championships in Tallinn she placed 8th in the short program, and 13th overall.
In the 2015–2016 season, Saarinen was assigned to the 2015 Tallinn Trophy, but withdrew before the short program. In December, she won the silver medal at the 2016 Finnish Figure Skating Championships, only 0.15 points behind the gold medal winner. She was 3rd in the short program, and won the free skating.