Ndong was born on 19 September 1998 in the village of Mbom-Esisis, located in Niefang District [es], Centro Sur Province, Equatorial Guinea.

[2] Ndong was selected to make his international debut at the 2021 FINA World Swimming Championships (25 m), although he ended up being a non-starter in both his scheduled events, the 50m and 100m freestyle.

[6] He also participated at the 2022 World Aquatics Championships in the 50m freestyle, being unable to advance past his heat with a time of 29.48 seconds, although a personal best.

[4][5] He competed for Equatorial Guinea at the 2023 African Games, hosted in Accra, and set a personal best time in the 50m butterfly at 32.54s, only eight-hundredths of a second slower than the national record, although he placed fourth in his heat and failed to advance.

[8] Along with Sefora Ada Eto, Ndong served as the co-flag bearer for his country at the opening Olympic ceremony.