[8] Day one of the 2021 World Short Course Championships, contested in December in Abu Dhabi, United Arab Emirates, Miressi led-off the 4×100 metre freestyle relay with a 46.12 in the final, contributing to a new Italian record time of 3:03.61 and a silver medal-win.

[15] At the 2022 World Aquatics Championships, with swimming competition held in June at Danube Arena in Budapest, Hungary, Miressi won a bronze medal as part of the 4×100 metre freestyle relay in a time of 3:10.95.

[33] In the preliminaries of the 50 metre freestyle on day six, Miressi was the third-fastest Italian with a time of 22.26 seconds, ranked eighteenth, and did not advance to the semifinals.

[40] Later in the day, he helped set a new word record in the event with a 3:02.75 to win the gold medal, contributing a lead-off time of 46.15 seconds to the final mark.

[45] For the final of the 100 metre freestyle in the evening session, he won the bronze medal with a personal best time of 45.57 seconds that tied his Italian record in the event.

[47][49][50] For the preliminaries of the 50 metre freestyle on the fourth morning, Miressi achieved a personal best time of 21.17 seconds, qualifying for the semifinals tied in rank for twelfth overall.

[56][57] At the 2023 Italian National Spring Championships in April in Riccione, Miressi won the silver medal in the 50 metre freestyle on day one with a time of 22.12 seconds.