Rivas took part in FIS races from winter 2001/02 and from the next season also in the French championships and junior championships. After several podium places in FIS races, it was used for the first time in the European Cup in December 2005 . In March 2006, he took part in the Junior World Championships in the Canadian province of Québec , where his best result was a 14th place in slalom. From January 2007 Rivas started regularly in the European Cup, but never won points in his 24 races up to the end of the 2007/08 season - mostly slalom and giant slalom. He came closest to the points with the 31st place in the slalom of Donnersbachwald on January 13, 2007, in which he was only three hundredths of a second short of a top 30 place - and thus a point win.
From 2008 to 2011 Rivas studied at the University of Colorado in the United States , which is why he participated almost exclusively in competitions in North America during this time and instead of the European Cup , he started in the Nor-Am Cup . After several victories in FIS races at the end of 2010, he celebrated his first victory in the Nor-Am Cup on January 3, 2011 in the slalom of Val Saint-Côme . The second followed at the end of the 2010/2011 season in the Whistler slalom . In the slalom discipline ranking he reached third place.
After completing his studies in the USA, Rivas started again in the European Cup from December 2011 - now with points. On January 15, 2012 he made his debut in the Ski World Cup ; he finished 25th in the Wengen slalom and immediately won his first World Cup points. The best World Cup result of the season was the 22nd place in the slalom in Bansko on February 19, 2012. After the end of the season, he was accepted into the B-team of the French Ski Association. On December 15, 2012 Rivas celebrated his first European Cup victory in the City Event of St. Vigil . A month later he achieved his best ever World Cup result with 18th place in the Adelboden slalom .
France