Background and Context: Computational thinking (CT) is a critical part of computing education in middle school. The existing practices of collaboration and collaborative design activities at this education level pairs well with CT practices, but this interaction has previously been under-explored in the existing literature. Objective: In this study, we investigate whether students can learn CT through collaborative design activities and what patterns emerge over time and across instructional phases. Method: We coded 6.3 hours of video observations for CT practices to create visualizations of 10-second segments of middle school students programming together. We use these visualizations to unpack nuances regarding how students demonstrate CT practices. Additionally, we provide three vignettes to highlight the interactions between students within and across the three instructional phases. Findings: The findings suggest that middle school students can learn CT concepts and practices through collaborative design activities. The results demonstrate the patterns of CT practices and detail the transitions between each CT practice over time within a small group. Implications: This study applies novel analysis techniques on student interaction data to examine CT through collaborative design. By bridging a CT framework with collaborative design activities, this study enhances the understanding of CT in collaborating, learning, and creating computing project-based designs.