During the last decades, collaborative learning as a pedagogical strategy in HE has been attracting growing interest by both scholars and practitioners. However, its methodological potential is still insufficiently used in practice, especially in the virtual context. This paper provides deeper insights into the challenges of designing formative feedback in virtual group work from an e-tutors perspective. Therefore, seven expert interviews were conducted to investigate how formative feedback can be designed in the group development phases according to Tuckman &Jensen (1977). The interviews were analyzed using qualitative content analysis according to Gläser &Laudel (2010). The applied codes were formed both deductively and inductively and discussed afterwards. In line with other studies like Johnson et al. (2002), the results have revealed that Tuckman's group phase model is also applicable in virtual settings. In a further step, this paper derives practical implications for e-tutors by identifying specific guidelines on how to structure formative feedback in each of the group development phases.