The Department for Evaluation, Prospective and Performance (DEPP) at the French ministry of education provides deciders with data analysis on the state of the French educational system. French students’ performance is measured through Large Scale Assessments (LSA). From 2018, DEPP’s LSA instruments are computer based when it comes to assess secondary school students. In mathematics, new test instruments have been developed embedding digital tools in support of the mathematical task. This paper presents the results of a study aiming at profiling student’s mathematical activity, based on a “big-data” analysis of the digital traces left in technology enriched interactive items by a sample of 9-graders in France. Results give hard evidence of how data science in education can benefit from the mixed contribution of three paramount aspects: technology, analytics and didactics.