He grew up in Cantagalo, a neighboring community of Cantagalo–Pavão–Pavãozinho, a group of favelas in the South Zone of Rio de Janeiro, renowned for producing numerous jiu-jitsu champions.

[1] From a young age, Jansen began training Brazilian jiu-jitsu under the influence of his brother, Jonata Gomes, and his father, Antônio Carlos "Bode," who holds a black belt in BJJ.

[1] Gomes achieved recognition as one of the top young athletes in Brazil when he was just a yellow belt, winning his first National title.

[1] At the 2023 World Jiu-Jitsu Championship, Gomes defeated Tainan Dalpra by way of tiebreaking advantages, 0x0, 2–0, in the final of the middleweight division.

[11] Gomes challenged Fellipe Andrew for the medium-heavyweight title in the main event of BJJ Stars 14 on December 7, 2024.