In the autumn of 2013 she moved to Mannheim to train under coach Valerij Bauer alongside former European champion Verena Sailer.

[6][7] At the 2014 European Athletics Championships in Zürich, she broke her own national record in the heats and semi-finals of the 100 metres competition before finishing fourth in the final.

[8] Kambundji qualified for the Swiss team at the 2016 Summer Olympics in Rio de Janeiro, reaching the semi-finals of both the 100 m and the 200 m events.

[11] In the 4 × 100 m relay event, she and her teammates Ajla Del Ponte, Sarah Atcho and Salomé Kora improved the national record in the semi-finals[12] and finished fifth in the final.

At the European Championships in Berlin, she finished fourth in the 100 m as well as in the 200 m and in the 4 × 100 m relay (with Ajla Del Ponte, Sarah Atcho and Salomé Kora).

On 19 August 2022, Kambundji won the gold medal in the 200 m at the European Athletics Championships in Munich with a time of 22.32 s, after winning silver in the 100 m in 10.99 s behind Germany's Gina Lückenkemper three days earlier.

[20][21] ETH Zurich student organization Swissloop's entry to the 2018 edition of the Hyperloop competition was a transport capsule named Mujinga, after Kambundji.