This study examines the needs of urban primary school Mathematics teachers as the basis for designing the MyTracking system for consistent, data-informed recording and sharing of Classroom-Based Assessment (CBA). A qualitative approach was employed through semi-structured interviews with three upper primary teachers. Transcripts were thematically analyzed to identify challenges, needs and critical functions. The findings indicate the burden of manual recording, large class sizes, misaligned records, limited parental access and time constraints that delay feedback. Key needs include a user-friendly system with easy access, record structures organized by topic and mastery level, progress visualizations, automated reporting and ongoing training. CBA operates through a cycle of feedback, intervention and reflection that enables targeted interventions, continuous monitoring and pupil self-reflection. Based on the findings, MyTracking is proposed to integrate evidence management, analytics, progress displays, action notifications and channels for sharing with parents and the school. The implication is that this user-centered design is expected to enhance teacher efficiency, communication transparency and the effectiveness of evidence-based follow-up actions.