Ilves won the ski jumping title at the 2010 Estonian Championships. He made his international debut as a combiner at the Nordic Junior World Ski Championships in 2011 in Otepää . In the Gundersen singles on the normal hill, he reached 48th place. In the team competition he was tenth with the team. After he narrowly missed the title in ski jumping with second place at the Estonian championships and also won silver in the team competition, he achieved the bronze medal in the team sprint combination. From March 2011 he started in the Nordic Combined Continental Cup . In the team sprint in Kuopio he was 12th together with Han-Hendrik Piho and achieved 47th place in the individual on the large hill and thus clearly missed the points.
At the 2012 Winter Youth Olympic Games in Innsbruck , he reached seventh place in the individual competition. After the games, he started again in the Continental Cup in Kuopio but, as before, was unable to achieve top placements. Even at the Grand Prix in Oberwiesenthal in summer 2012 , he remained unsuccessfully in the back of the list.
In January 2013, Ilves managed to achieve a top 20 position for the first time at the Continental Cup in Klingenthal with 16th place and also his first point win. At the Nordic Junior World Ski Championships 2013 in Liberec , he won the Gundersen singles on the normal hill and the bronze medal over five kilometers. In the team competition he was eighth with the team and in the Gundersen individual on the normal hill and reached 10th place over 10 kilometers. On February 2, 2013 he made his debut in the Nordic Combined World Cup in Sochi . After a 41st place in the individual, he reached the 12th and last place in the team competition with the team, which also included Han-Hendrik Piho , Kail Piho and Karl-August Tiirmaa . At the Nordic World Ski Championships 2013 in Val di Fiemme , Ilves took 48th place in the Gundersen singles.
On January 5, 2014, Ilves won his first point in the World Cup in Tchaikovsky . This enabled Ilves to qualify as one of three Estonians for the Olympic Games in Sochi . He finished 41st in the competition on the normal hill and 34th on the large hill.
At the Nordic Junior World Ski Championships in 2015 and 2016 , he was able to confirm his performance from Liberec and again won the bronze medal in the sprint. In addition, he was finally able to establish himself in the World Cup and in the Estonian top during these years. In the summer of 2015, he celebrated winning the Estonian championship in Nordic combined for the first time, which he was able to repeat six more times until winter 2019.
In 2016/17 Ilves competed in the Continental Cup four times and reached the podium every time. At the end of January 2017, Ilves won his first Continental Cup competition in Otepää , which he was able to repeat twice in Eisenerz in February . At the Nordic World Ski Championships 2017 in Lahti , Ilves competed in all four competitions, with his best individual result being 23rd in the Gundersen competition on the normal hill. In the 2017 Summer Grand Prix , Ilves achieved his first two placings in the top five and was finally able to finish the overall ranking in fifth place. He was able to show these good performances also in the winter of 2017/18 by reaching the podium for the first time on February 4, 2018 in Hakuba, Japan, with a second place and ultimately finishing the World Cup season in nineteenth place. Ilves shows his best performances especially in jumping, so that he took eleventh place in the jumping competition. At his second Olympic Games in Pyeongchang , he missed a surprise and finished 16th on the normal hill and 28th on the large hill.
In the winter of 2018/19 Ilves struggled continuously with form problems, so that he rarely reached the points. His best World Cup result of the winter was 23rd in Chaux-Neuve . He closed the season at the end of March with his seventh championship title in Nordic combined, as well as with the bronze medal at the Estonian ski jumping championships .