The article describes a technology-mediated collaborative peer-feedback experience. 125 students took part into the activity during the delivery of a 3-months teaching in “Methodology of Action Research”, within a 3-year Degree Course in Psychological, Social and Occupational Sciences. The activity was based on a 4-phases cycle of collaborative output production, structured peer-feedback, collaborative output improvement, individual reflection. The aim of the exploratory case-study here presented is to observe if and how the peer-feedback activity supported the development of collaborative, meta-cognitive and digital skills, other than knowledge acquisition. To answer our research questions, we used a mixed system, able to provide both objective data with respect to the activity carried out and the skills put in place, and subjective data related to the students' personal experience and the perceived impact on their learning. Results show a good appropriation of metacognitive skills and offer numerous hints on the design aspects which have been found to be effective in supporting students’ learning.