Swansea City De Boer played youth football for
FC Volendam,
Ajax and
Swansea City. He made his professional debut for Swansea's first team in a 3–1 home win over
Northampton Town at
Liberty Stadium in the
EFL Cup. De Boer replaced
Yan Dhanda in the 90th minute.
ADO Den Haag On 2 June 2020, De Boer signed a two-year contract with
Eredivisie club
ADO Den Haag, after his contract with Swansea had expired. He made his ADO league debut on 13 September 2020 in a 2–0 away loss to
Heracles Almelo. After a disastrous season, in which ADO finished bottom of the league and suffered relegation to the
Eerste Divisie, De Boer exercised a relegation option in his contract to leave the club as a free agent.
VVV-Venlo De Boer joined
VVV-Venlo, who had suffered relegation alongside ADO, on 6 July 2021, signing a two-year contract with an option for an additional season. He was in the starting lineup on his debut for the club, a 2–2 home draw on the opening day of the
2021–22 season. De Boer left VVV at the end of the
2022–23 season, as his contract was not extended.
Ternana On 15 September 2023, De Boer officially joined Italian side
Ternana on a
free transfer, signing a one-year contract with the club, with an option for another season. ==International career==