At the 2013 World Junior Curling Championships, Mosaner led his team of Pilzer, Daniele Ferrazza, and Roberto Arman to a 6th-place finish (5-4 record).

Finally, at the 2015 World Junior Curling Championships, he was less successful, leading his team of Sebastiano Arman, Carlo Gottardi and Fabio Ribotta to an 8th-place finish (3-6).

After a 4-3 round robin record, he led his team of Denise Pimpini, Alessandro Zoppi, and Adriana Losano to playoff wins against the United States and Canada before losing to Switzerland in the final.

After finishing the round robin in 2nd place with a 7-2 record, they lost all of their playoff games, including the bronze medal match, settling for 4th.

The team finished 8th at the 2017 European Curling Championships but had much more success a month later at the 2018 Winter Olympic Qualification Event.

Mosaner played third for Italy at the 2018 European Curling Championships, where the country won its first medal at the event since 1979, picking up a bronze.

The pair missed out on the playoffs as their draw shot challenge (DSC) record was not good enough compared to the other third-place teams.