At the Nordic Ski Games of the OPA 2015 in Seefeld , he took fourth place in the Gundersen competition for students from the middle hill and over 4 km. A year later he repeated these two placements in the junior competitions of the OPA ski games 2016 in Tarvisio and Villach . At the end of the season, Vallet made his debut in the Continental Cup in March 2016 , but missed the points in Chaux-Neuve.
In February 2017 Vallet took part in the Junior World Ski Championships in Park City , but was only nominated for the sprint in which he finished twentieth. A year later in Kandersteg , he completed all three competitions. He was tenth in the individual, eleventh in the sprint and fifth in the relay. A week later, Vallet won his first Continental Cup points when he reached positions 18 and 24 in Eisenerz, Austria . In March he made his World Cup debut in Lahti , but did not get past 49th place. At the end of the season, Vallet was French ski jumping champion with the team in Les Rousses .
In the summer of 2018, Vallet scored his first points in the Grand Prix in Villach and repeated this two days later in Oberstdorf . At the beginning of the 2018/19 season he tried again in the World Cup, but initially failed due to his poor jumping form. That is why Vallet competed in lower-class competitions in the following weeks, where he was to take his second victory in the Alpine Cup. He was able to confirm this performance in the Continental Cup, where he was among the top ten in Eisenerz. At the end of the season in Schonach , Vallet was reappointed to the World Cup team. With a 27th place, he won his first four World Cup points.