[8] Being a Swiss player from Basel who employs a one-handed backhand and represented TC Old Boys, Bernet has often drawn comparisons to Roger Federer.

[9][10][11] In May 2022, Bernet won the J5 event in Jönköping after defeating top seed Saba George Nanobashvili in the final.

[18] The following month, he reached the semifinals of the U16 Tennis European Junior Championships in singles and won the doubles title with compatriot Flynn Thomas.

[19] In January 2024, he reached the final of the J200 Slovak Junior Indoor event in Bratislava, but lost to top seed Denis Peták.

In April, he reached the final of the J300 Tournoi de Tennis ITF Junior in Beaulieu-sur-Mer, but lost to Nicolai Budkov Kjær.

[28] He upset Juan Pablo Varillas the second round, making him the first player born in 2007 or later to reach the quarterfinals of a Challenger tournament.

[29][30] Later that year, he made his ATP Tour debut as a wildcard into the doubles main draw of the Swiss Indoors with compatriot Jérôme Kym.