[2] De Jong has won three singles and seven doubles titles on the ATP Challenger Tour.

[8] De Jong and his grandfather, Jan, who died in October 2023, had dreamed of playing in a Grand Slam.

After qualifying for the main draw of the 2024 Australian Open, de Jong got a tattoo to commemorate his late grandfather.

[10] In May, he won his second Challenger doubles title, this time with Tim van Rijthoven, at the Open de Oeiras IV.

[15][16] Following a semifinal showing at the Challenger in Traralgon, Australia in January, he made his debut in the top 200 on 14 February 2022.

He made his ATP main draw doubles debut after qualifying as a pair partnering Sem Verbeek at the 2022 ABN AMRO World Tennis Tournament in Rotterdam.

He qualified for the 2024 Australian Open making his Grand Slam debut[18][19][20] and defeated Pedro Cachin for his first Major win.

De Jong's record against players who has been ranked in the top 10 in their career, with those who are active in boldface.