On 14 January 2006, he scored the first points in the FIS Ski Jumping World Cup, taking 22nd place in the competition in Harrachov.

On 2 March 2013 he won there a bronze medal in team competition with teammates: Kamil Stoch, Maciej Kot, Piotr Żyła.

[3] Kubacki jumped 126 m and 128 m. The primary outcome of the competition his team took fourth place, but after re-counting the scores because of Thomas Morgenstern, who noticed a mistake in points and at the request of the Germans, they finished in third place (Norway was in front of the Polish, but Bardal's jump was badly counted).

[10] He maintained the winning streak of Poles in this tournament, repeating the success of Maciej Kot from the last year.

Kubacki achieved good results since the very start of the winter season after winning the overall classification of the Summer Grand Prix.

On 30 December 2017, Kubacki reached the lowest level of the podium in Oberstdorf, behind the winner Kamil Stoch.

[15] On 19 February 2018 Kubacki and his teammates Maciej Kot, Stefan Hula and Kamil Stoch achieved first medal in Olympic team competition for Poland.