This study explores the use of coach-guided retrospectives as a pedagogical tool to enhance team communication, feedback culture, and reflective practice among undergraduate computer science (CS) students. Five student teams participated in a 90-min, milestone-aligned retrospective session facilitated by a trained coach using a digital whiteboard platform. The session followed a structured format focusing on positive highlights, areas for improvement, and actionable next steps, with a dedicated space for peer appreciation to foster psychological safety. A mixed-methods evaluation was conducted using post-session surveys, in-session debriefs, and follow-up interviews. Findings suggest that coach-led retrospectives helped students engage in more open and constructive feedback, improved communication dynamics, and fostered a stronger sense of team cohesion. Students reported increased confidence in giving and receiving peer feedback and found the sessions unexpectedly engaging and useful. Notably, several teams voluntarily extended the retrospective model across future milestones. These outcomes indicate that structured, facilitator-supported retrospectives can serve as more than a professional simulation; they can also be powerful interventions for cultivating essential teamwork competencies in educational settings. The study contributes to the discourse on agile-inspired pedagogy by demonstrating how reflective rituals, when scaffolded thoughtfully, support psychological safety, collaborative learning, and continuous improvement in team-based computing courses.