Gymnastics career
2016
Osyssek competed at the European Championships where she helped France finish fifth as team in the junior division. Individually she placed sixth in the all-around and fifth on vault.
2022
In June, Osyssek competed at the Mediterranean Games, where the French team took the silver medal behind Italy. Individually Osyssek won the silver medal on vault and the bronze medal on floor exercise. At the European Championships in Munich, France finished sixth in the team final. Additionally Osyssek placed seventh on floor exercise.
In October, Osyssek was named as the alternate for the World Championships team. In November, she competed at the Arthur Gander Memorial where she placed third behind Alice D'Amato and Lena Bickel.
2023
Osyssek competed at the DTB Pokal Team Challenge where she helped France finish third. She later competed at the European Championships where she helped France finish sixth; individually she finished thirteenth in the all-around. In August she was named to the team to compete at the World Championships.
At the World Championships Osyssek contributed scores on balance beam and floor exercise towards France's historic bronze medal winning performance. Individually Osyssek was initially the first reserve for the all-around final. She was substituted in when Ou Yushan of China withdrew; she finished fourteenth.
