Janda made his World Cup debut in 1996 but had to wait until 2003 for his first major success, which was third place in Liberec. Janda improved his performance under new Slovenian coach Vasja Bajc in 2004. In 2004–05 season he managed to collect several second and third places and one victory in World Cup events. He also gained a silver and a bronze medal at the 2005 FIS Nordic World Ski Championships in Oberstdorf. Janda started 2005/06 season with World Cup wins in Kuusamo, Lillehammer, Harrachov and Engelberg, and entered the Four Hills Tournament leading the World Cup standings. In the opening event in Oberstdorf, Janda finished in third place to place high for the second round, with Janne Ahonen in first and Roar Ljøkelsøy in second. After winning the second race of the Tournament in Garmisch-Partenkirchen, Janda moved to second place in the standings behind the reigning Tournament champion Ahonen. Norway's Lars Bystøl was the unexpected winner in Innsbruck while Janda finished ahead of Ahonen for the second straight time to move into a two-point lead before the last competition. Like in all previous rounds Janda advanced in last place into the competition to having skis that were too long during Oberstdorf qualifying and could not participate in the next three qualifying rounds as a result. The tournament climaxed with a Janda vs. Ahonen knockout duel. Janda won the first round by one point, then increased his lead to three points before the last jump. Ahonen beat Janda in the last jump by 141.5 meters to 139 meters and won the Bischofshofen competition by two points. The overall standings thus had both jumpers tied for first place, the first ever joint victors in the history of the tournament. Norway's Ljøkelsøy finished third. Jakub Janda was the first Czech winner of the Tournament since Jiří Raška won it in 1971. Janda then experienced a drop of form, leading to poor results at the 2006 Winter Olympics in Turin, finishing 13th in the individual normal hill, 10th in the individual large hill and 9th in the team large hill. After the Olympics he managed to return to the podium in the World Cup event, but his form was less solid in comparison to the beginning of the season. His biggest rival Janne Ahonen tried to take advantage of it, but also struggled and after disappointing Lahti results on the eve of the end of the season, he decided to withdraw from one race of the World Cup to concentrate on the last events in Norway and on mammoth hill in Planica. Janda's lead grew to 175 points with 200 points to gain in the last round in Planica. Janda announced he did not want to participate in the ski flying event, but had to compete in Planica to secure his overall title. Qualifying last to the final round of the first of two Planica races and finishing 29th after the second jump, he was helped by Ahonen, who did not reach a better result than 11th place. Janda did not enter the last race and finished the World Cup standings with 1151 points, 127 ahead of Ahonen. He was the first Czech that won the ski jumping World Cup ever, and more – no Czech skier had ever won the Olympic discipline World Cup standings before. Coach Vasja Bajc, who is widely considered the driving force behind Janda's rise to fame, ended his relationship with the Czech team after the season and was replaced by an Austrian, Richard Schallert. Janda has competed in three Winter Olympics, earning his best finish of seventh in the team large hill event at Vancouver in 2010 while his best individual finish was 13th in the individual normal hill event at Turin four years earlier. On 2 October 2017 he made his last official career jump when he stuck at the qualification round of Grand Prixseason final competition in Klingenthal. Only three weeks later he became a politician.
Politics
He participated in 2017 Czech legislative election and was elected into the parliament as candidate of the Civic Democratic Party. At the same time he was elected in Czech parliament he officially ended his ski jumping career.
