Sjøen made his international debut at an FIS Cup in Notodden . A year later he achieved his first podium placement there in the same competition. In January 2012 Sjøen started in the Continental Cup for the first time , where he could not collect any points.
After several appearances in the Summer Continental Cup, in which he scored points with two top ten results, he started at the Grand Prix at the end of September 2013 . With 26th place in Klingenthal , he secured 81st place in the final ranking.
His most successful World Cup year to date was the 2014/15 season . In this he made it into the finals of the 30 best ski jumpers a total of eleven times, his best competition result was a seventh place in Sapporo in January 2015. In the previous summer he had also achieved many strong placements at the 2014 Grand Prix , including two wins in Hakuba in August 2014, so that in the end he won second place in the overall Grand Prix standings, one of his best results ever.
Norway
