Jäämies made his international debut for Finland at the 2012 European Mixed Curling Championship, winning a bronze medal playing second on the team. Later that year he played for Finland at the 2012 European Curling Championships. The team, skipped by Kauste finished 11th place, and qualified for the 2013 Ford World Men's Curling Championship. At the Worlds, the Kauste rink finished last (12th), with a 2-9 record. Later in the year, the team played in the 2014 Olympic qualifying event, but failed to qualify having won just two games.