What recruiters expect from working-student applications
Working-student positions are assessed differently from full-time junior roles. Recruiters scan three things in the first 8 seconds: field of study + semester (does it fit the task?), available weekly hours (max. 20 during term time) and earliest possible start date.
Place these three pieces of information prominently in the CV header or in the first paragraph of the cover letter. Don't hide them between hobbies and language skills.
In addition: recruiters are used to typical student clichés from thousands of CVs. “Quick to grasp things”, “team player”, “resilient”, such empty phrases don't work. More effective are concrete proofs: “Tutor for Mathematics 1, 30 students per exercise group” says more than three adjectives.