De Rosa grew up in Naples and began competitive motorcycle racing in the Italian domestic 125cc Championship, contesting it from 2003 onwards on Aprilia and Honda machinery. His results improved steadily, and by 2005 he had made his FIM World Championship debut in the 125cc class, a competition he would continue to contest through the 2008 season on Aprilia and KTM machines. While he did not challenge for the 125cc world title, his years in the class gave him the technical foundation and track experience to advance to larger displacement categories.
De Rosa stepped up to the 250cc World Championship in 2009, riding a Honda RS250RW. He made an immediate impact, finishing sixth overall in the standings and earning the Rookie of the Year award — a strong debut result in a class that was in its final season before transitioning to the four-stroke Moto2 format. He continued in the Moto2 World Championship through 2010 and 2011, competing with Tech 3 and subsequently on Moriwaki, FTR, and Suter machinery, though the results were less competitive as the field in the new class grew rapidly in depth.
From 2012, De Rosa shifted his focus primarily to the Supersport World Championship, where he competed aboard Honda CBR600RR machinery in his first three seasons. He found a more natural fit in the WorldSSP class, gradually improving through the standings and becoming a consistent midfield finisher. His best WorldSSP seasons came from 2018 through 2020, where he finished sixth overall in three consecutive years riding for MV Agusta with the F3 675 — a run of consistency that demonstrated his ability to extract the maximum from the Italian manufacturer's equipment.
The defining achievement of De Rosa's career came in the FIM Superstock 1000 Cup. After finishing third in 2015 aboard a Ducati 1199 Panigale, he returned in 2016 on a BMW S1000RR and won the title outright. The Superstock 1000 Cup — which ran concurrently with the Superbike World Championship — was a fiercely competitive class featuring production-derived machines with limited modifications, and De Rosa's championship win demonstrated his ability to perform at the front against a high-quality field.
Following his Superstock title, De Rosa stepped up to the full Superbike World Championship in 2017, again riding the BMW S1000RR. The move to WorldSBK placed him against the top-tier production superbike riders in the world, and he finished 15th overall in his debut season at the highest level of production-based motorcycle racing.
De Rosa continued competing in the Supersport World Championship into the 2020s, joining QJ Motor Factory Racing in the WorldSSP class as the Chinese manufacturer expanded its presence in international motorcycle racing. His long career — spanning from the 125cc world championship era through to the modern four-stroke WorldSSP grid — reflects both adaptability and sustained professional commitment across more than two decades of competition.
De Rosa's 2016 FIM Superstock 1000 Cup title stands as the central achievement of a career that touched almost every mainstream motorcycle racing category. His consecutive sixth-place finishes in WorldSSP from 2018 to 2020 on MV Agusta machinery further cemented his reputation as a reliable and experienced front-of-midfield competitor in international superbike-class racing.