The recent focus on graduate employability has exposed the inadequacies of work preparation for science students, who need an employability toolkit to navigate the complex modern work landscape. We implemented a novel peer mentoring activity that focused on work-capability development for Bachelor of Science undergraduate students. The student experience was evaluated using structured written reflections, student self-assessment, and interviews. Students were most likely to be challenged by the processes of articulating strengths and weaknesses and mentoring another student. Students' self-reported learning gains were coded against a framework for career management skills -- several were strongly evidenced. We found that the short-term mentor/mentee experience described here can pose students with a level of challenge, and that participation in this activity leads to changes in their self-awareness and development of their career management skills.