He made his World Cup debut in December 2018 in Val d'Isere, and collected his first points (five) with a 26th-place finish.

[9] Braathen recorded his first victory (and podium) in October 2020 at the season opener, a giant slalom in Sölden.

[10] He announced his retirement from World Cup racing on 27 October 2023, a day before the new season's opening event in Sölden, Austria.

[11] However, on 7 March 2024, Braathen announced that he would return to alpine ski racing; but competing for Brazil instead of Norway.

[12][13] On 27 October 2024, exactly a year after he announced his retirement, he returned at the World Cup Giant Slalom season opener in Sölden, narrowly finishing in 4th place behind the 1-2-3 podium clean sweep achieved by his former Norwegian teammates, scoring the first ever world cup points for Brazil in Alpine Skiing.