Born in Amstelveen, and growing up in Nieuw-Vennep, North Holland,[1] Stengs joined AZ's youth academy at the age of 12, having formerly played for local side SV DIOS and HFC Haarlem.

[4] His strong performances for the reserves were noticed by first team head coach John van den Brom, and on 5 March 2017, Stengs made his league debut for AZ in a 1–1 home draw against Excelsior in the Eredivisie.

[6] In the seventh minute of the match he twisted his knee and tore his anterior cruciate ligament, cutting his first professional season short.

[7] Stengs returned to first team action in November 2018 and reconquered his position in the AZ starting eleven, 15 months after his injury.

[12] On 14 July 2021, Stengs signed for Ligue 1 club Nice on a five-year contract for a transfer fee reported to be €10 million plus bonuses.

[27] On 26 July 2023, Stengs joined reigning Dutch champions Feyenoord on a four-year contract, where he reunited with Arne Slot, who also coached him at AZ.

[34] On 19 November 2019, Stengs made his debut for the Netherlands national team in the UEFA Euro 2020 qualifying match against Estonia, giving two assists in a 5–0 victory.

[35] On 21 November 2023, Stengs scored a hat-trick in the Netherlands' final UEFA Euro 2024 qualifier against Gibraltar to register his first senior international goals.