She rose to prominence after becoming the runner-up on the tenth season of Nouvelle Star, a French singing reality competition television series.

[3] She also worked with artists such as Kanye West, Black Eyed Peas, Rema, Anitta, Sevdaliza, Pabllo Vittar, Shygirl, and Ty Dolla Sign.

[4][5][6] She realized her talent at a young age, however, her father did not allow her to make music,[7][8] prompting Onguenet to skip classes to audition for Nouvelle Star in Paris.

She competed in the final against Mathieu Saikaly, the winner of the season, and performed songs such as "Roar", "Feeling Good", and "Wasting My Young Years" throughout her duration on the show.

[7] Following the show, Onguenet signed to Polydor Records under the name Yseult,[8] and announced that she was preparing her debut album, working with French composer and singer Emmanuel da Silva.

[12] The album's commercial performance was a disappointment for both Onguenet and her label, and influenced her decision to end her contract with Polydor a couple years later.

[13] In April 2017, she worked in a writing seminar for the Black Eyed Peas,[14] organised by Polydor, after which she decided to end her contract with the label later that year.