Bosker had his first international successes at the Junior World Championships 2015 in Warsaw . There he won the bronze medal in the all-around competition, the silver medal in the mass start and the gold medal in the team pursuit. The following year he won the bronze medal in the all- around and over 1500 m at the Junior World Championships in Changchun . He made his debut in the Speed Skating World Cup in January 2017 in Berlin . There he took first place over 1500 m twice in the B World Cup. In the 2017/18 season he achieved his first podium finishes in the World Cup in Erfurt with third place over 1500 m and in Minsk with third place over 5000 m. In January 2018 he won the bronze medal in the 5000 m and the gold medal in the team pursuit at the European Championships in Kolomna . He also ran there in fourth place over 1500 m. In Heerenveen he became Dutch champion in the great four-way battle. He won the bronze medal at the all-around world championships in Amsterdam in March 2018 . After third place over 5000 m and second place in the team pursuit at the first World Cup station in Obihiro at the beginning of the 2018/19 season, he won his first World Cup victories in the team pursuit in Tomakomai and over 10,000 m in Tomaszów Mazowiecki . At the individual distance world championships in Inzell in 2019 , he won the gold medal in the team pursuit. At the end of the season he was second in Salt Lake City over 5000 m and finally achieved second place in the overall World Cup over 5000/10000 m.
Personal bests
500 m 36.39 sec. (installed on March 18, 2017 in Calgary)
1000 m 1: 09.10 min. (installed on March 16, 2017 in Calgary)
1500 m 1: 44.12 min. (installed on February 7, 2020 in Calgary)
3000 m 3: 36.33 min. (installed on November 25, 2017 in Calgary)
5000 m 6: 08.90 min. (installed on March 9, 2019 in Salt Lake City)
10,000 m 13:07:01 min. (installed on November 3, 2019 in Heerenveen)
Netherlands
Tomaszów Mazowiecki
Tomakomai