The proliferation of social media platforms has transformed the landscape of education, fostering the emergence of peer learning communities within these digital spaces. This research investigates the dynamics of student engagement in social media-based peer learning communities, focusing on motivations, the influence of unique platform features, and the challenges that shape the learning experiences and outcomes. A mix-method was used to explore the most commonly used social media platforms for peer learning and their learning experiences within these communities among students from FPT University in Danang, Vietnam. The results shed light on the drivers of student engagement, the ways in which these motivations manifest in their interactions, and the obstacles students encounter in their learning journey. This study contributes to the existing body of knowledge, offering practical insights into the selection of platforms, strategies for fostering motivation, and the design of interventions to address challenges. The data collected from FPT University in Danang, Vietnam, adds a unique perspective to the global conversation on student engagement in the digital age.