Aji began his racing career in motocross at the age of 10 before transitioning to road racing. In 2018, he competed in the Idemitsu Asia Talent Cup (IATC), securing four podium finishes, including a victory, and finishing 5th in the overall standings. Simultaneously, he competed in the Asia Road Racing Championship (ARRC) AP250 class, finishing the season in 6th place.

Over the following three seasons, he competed in the Red Bull MotoGP Rookies Cup and the FIM CEV Moto3 Junior World Championship, consistently ranking within the top 15 in both series.

In 2022, he earned a full-time seat in the Moto3 class with Honda Team Asia. In his rookie season, he made a strong impression by securing a front-row start at his home Grand Prix in Indonesia. He finished the season with two points-scoring races and continued his campaign in 2023.

In 2024, Aji stepped up to the Moto2 class. Adapting to the intermediate category, he collected 4 points throughout the season, with a best finish of 15th. In the following 2025 season, at the third round (the Americas GP), he achieved a 9th-place finish—the best-ever result for an Indonesian rider in the class.

In 2026, his third year in Moto2, he continues as a member of IDEMITSU Honda Team Asia, aiming for consistent front-running results.