We study the experts' practices developed with the support of digital technologies (DT), when they take aware in-the-moment decisions during classroom discussions to promote the development of effective formative assessment (FA) processes. In this investigation, we complement a macro-analysis of paradigmatic examples of classroom activities, focused on the functionalities of DT and on the implemented FA strategies, with a micro-analysis, developed with reference to a theoretical construct useful for interpreting and analysing expert teachers' roles during classroom discussions (the Model of Aware and Effective Attitudes and Behaviours, MAEAB). More specifically, we explore how the expert uses DT to empower these roles with the aim of promoting FA processes. This study has two implications: (1) at the theoretical level, the study will introduce a model aimed at characterising the ways in which the expert can promote FA during classroom discussions when they are mediated by the use of DT; (2) at the pragmatic level, the use of this model to analyse paradigmatic examples from teaching experiments will introduce potential guidelines for teacher professional development aimed at promoting teachers' autonomous use of DT to carry out effective FA practices.