Hagin first started racing at the age of eight, when the young German took up go karting. It took him almost a decade to make the move to water, as he began racing motorboats at the age of seventeen.

His competitive racing career started in the F5 category, in which he raced for two years in the German national championship.

He then made the step up to F4, where he competed in national, European and world championships, becoming F4 World Champion in 2009 and European Champion in 2010, as well as winning three German national championships. He made the move to F2 in 2011, going on to win the F2 World Championship in 2022.

His constant career successes saw him get the call up to F1 in 2025, where he made his debut for China CTIC Team at the Grand Prix of Jeddah.