The purpose of this article is to describe as closely as possible the professionality created by the adaptation of two teachers to a non-traditional teaching project brought about by institutional orders. The didactic perspective assumes that beyond the particularities of the teaching environments, the challenges of learning knowledge in and through the relationship between teachers and learners are the main organisers of teaching and learning practices. The longitudinal clinical didactic analysis of co-intervention in a school discovery route helps to understand how teaching professional skills are built together in an interdisciplinary system.