Hojer started participating in German Lead climbing youth competitions in 2004, at the age of 10.

Notable results started coming next year, when he ranked fifth in the Climbing World Championships.

He won the seasonal title of the Bouldering Climbing World Cup in 2014 and finished second in 2015.

[1] Also in 2017, he won the silver medal at the Bouldering World Games in Wroclaw, Poland.

In 2018, he made the third ascent of the deep-water soloing route, Es Pontàs at 9a+ (5.15a).