Rubuta ci gaba don wannan sakin layi - Kosi ya fara gasar cin kofin duniya a watan Maris na 2011 a Kranjska Gora, Slovenia. Ya halarci Gasar Cin Kofin Duniya ta 2013
, inda kyakkyawan sakamakonsa ya kasance wuri na 12 a cikin haɗin gwiwa. Kosi ya wakilci Slovenia a wasannin Olympics na hunturu na 2014, inda ya kai matsayi na 24 a cikin saukowa.