[3] He is considered to be a classics specialist, and has won several major races including the 2021 Milan–San Remo, one of cycling's monuments, the 2020 Omloop Het Nieuwsblad and the 2016 Kuurne–Brussels–Kuurne.

He began his professional career at age 20 for Bontrager–Livestrong; he earned four victories with the team, including the Volta ao Alentejo.

He was named in the start list for the Tour de France[8] where he held the polka-dot jersey as leader of the mountains classification for two days.

In 2018, Stuyven finished in the top 10 in many of the spring classics, including 4th place in Omloop Het Nieuwsblad,[12] and 5th in Paris–Roubaix, being part of the chase group with Sep Vanmarcke and defending champion Greg Van Avermaet.

In September, he first won the Grand Prix de Wallonie, before winning his home town race in Leuven, the Grote Prijs Jef Scherens.

Many of the main pre-race favorites in the lead group were hesitant to chase him down, though Søren Kragh Andersen managed to bridge across to Stuyven in the final kilometer.

Outside of cycling, he and his uncle Ivan, an experienced chocolatier, run a small chocolate boutique in Betekom named Chocolade Atelier Stuyven that opened in 2016 and often produces many cycling-themed pieces.