The snowboarder , who comes from the Seen district of Winterthur, made his debut in the Snowboard World Cup in December 2015 in Montafon , where he finished in 15th place. In the two subsequent races he also qualified for the round of 16 for the best 48 drivers - an achievement that, according to his trainer, no other Swiss driver has achieved before him. As a member of the B-squad, however, he did not contest the World Cup races in Russia and Spain, otherwise he was represented by invitation. At the Snowboard Junior World Championships 2016 at the end of March, he and Jerome Lymann won gold in the team competition, in the individual competition he was twenty-fifth. At his first Swiss championships in February 2016, he took silver behind Lymann after there was no parade in snowboard cross the previous year. In the following season, Koblet was already part of the World Cup team and consequently competed in all races, but made it into the top 18 only once - in contrast to last season, when he achieved this three times. Koblet explained this by the fact that he was now driving faster and was therefore no longer able to benefit as well from falls in the field. At his last Junior World Championships in the same season, however, he was able to convince and became Junior World Champion in the individual competition. He won bronze at the Swiss Championships in 2017.
Thanks to meeting the B-limit, Koblet was selected to participate in the Winter Olympics in Pyeongchang at the end of January.