This study investigates student interaction and engagement in Twitter-supported collaborative learning, focusing on cognitive and socio-emotional processes, their evolution, and their impact on knowledge construction and group project outcomes within a higher education flipped classroom context. Utilising mixed methods analysis, including qualitative content analysis and Generalized Linear Mixed Models (GLMM), tweets from 28 s-year Guidance and Psychological Counselling students were analysed during weekly tweeting (WT) and live chat (LC) activities over a 10-week period. Findings reveal distinct engagement patterns in both activities. Asynchronous WT activities primarily supported reflective individual cognitive engagement with minimal socio-emotional interaction. Conversely, synchronous LC activities fostered dynamic, interactive cognitive engagement and richer socio-emotional interactions. LCs more effectively promoted self and social regulation of socio-emotional processes, while both activities showed few instances of social regulation of cognitive processes. Temporal analysis indicated significant fluctuations in cognitive engagement during WT activities, whereas LCs showed a consistent increase in cognitive engagement and fluctuations in socio-emotional engagement. GLMM analysis highlighted a significant, positive relationship between cognitive and socio-emotional engagement over time. Different types of engagement had distinct impacts on learning outcomes. Cognitive engagement in LCs strongly correlated with social knowledge construction and group project success, while in WT, it linked to individual knowledge construction and group project outcomes. Socio-emotional engagement significantly correlated with social knowledge construction in LCs, and the regulation of socio-emotional processes positively influenced social knowledge construction only in WT activities. This study emphasises the distinct ways Twitter facilitates engagement and learning, underscoring the role of activity design in fostering cognitive and socio-emotional processes. It also underscores how social media can be effectively integrated into a flipped classroom setting to substantially enhance collaborative experiences and learning outcomes in higher education.