Bosse won the bronze medal in the 800 metres at the 2012 European Championships held in Helsinki.

On 18 July 2014, Bosse ran his personal best time (1:42.53) at the 800 metres race at the Herculis meet, a Diamond League meeting held in Monaco; he finished the race in second place behind Nijel Amos of Botswana.

[citation needed] [3] On 8 August 2017, he won the men's 800 m at the IAAF World Championships in London in a time of 1:44.67.

[4] However, with Bosse not having run close to the world lead, and having to start his season late due to injury he was not considered a favorite.

[citation needed][6] Bosse announced his retirement from the sport in December 2023, following a string of injuries.