This paper presents the qualitative part of an overarching study elaborating student engagement in compulsory K-12 computer science (CS) courses. This initial qualitative study investigates 11th graders’ interest in CS after taking CS courses taught using a broad curriculum. For this important matter of student learning success, this study draws from the person-object theory of interest. Existing measures used for the same purpose were designed for other K-12 disciplines (especially science education) and therefore lack a domain-specific characterization. By investigating ten 11th and 12th graders’ attitudes and beliefs formed in elective and compulsory CS courses they attended in advance, we derived a specific person-object relationship (POR) that is captured by three key dimensions of their engagement: everyday life, activity and individual learning design.