[5] At the 2022 European Junior Swimming Championships, held in Otopeni in early July, Stancu won his first medal on day one as part of the 4×100-metre freestyle relay, swimming the second leg of the relay in a time of 51.11 seconds in the final to contribute to the gold medal-winning time of 3:18.93.

[9][10][11] In the final, he tied Krzysztof Chmielewski of Poland for the silver medal with a time of 3:50.61, finishing 2.47 seconds behind gold medalist in the event Lorenzo Galossi of Italy.

[16] Day one of the 2022 FINA World Junior Swimming Championships, held starting 30 August in Lima, Peru, Stancu ranked third in the preliminary heats of the 400-metre freestyle with a time of 3:51.43 and qualified for the final.

[33] At 17 years of age at the 2023 Romanian Championships in April in Otopeni, Stancu won the senior and youth national titles in the 800-metre freestyle with a time of 7:58.38 on day one.

[35][36] Day five of five, he won the senior and youth national titles in the 1500-metre freestyle in a time of 15:22.45 and won a youth national title in the 4×100-metre medley relay, helping achieve a time of 3:54.35 by swimming the butterfly leg of the relay.