Students and professionals with background in technical subjects are increasingly opting for a teaching career as a result of a conscious plan from the Swedish government to facilitate transition and completion of a teaching degree. One of the expected benefits from this measure is that students with broader academical and professional experiences could bring that knowledge into their future teaching practice and share it with in-service teachers during their practicum. The purpose of this study is to understand the subjectivities and practices of teachers and pre-service teachers as they engage in professional development activities together. Michel de  Certeau’s work on practices of everyday life serves as a lens for bringing forward the tensions and opportunities that appear in cooperative learning settings within external policy constrains. The motivations of mathematics teachers and preservice teachers that participate in computer programming training activities are analyzed in terms of tactics and strategies that preserve individual autonomy and group coherence and that allow them to make their own spaces within imposed structures. Some teachers resorted to avoidance tactics to escape reporting about their programming assignment, such as postponing it to future meetings or claiming time constrains, while others considered programming  activities  as  intruders  that  obstructed  their mathematics lessons and introduced moments of struggle, deception, confrontation and resignation. This sheds light upon how the practical and intellectual production that schools expect to reap from the process is disseminated increative alliances but leaves also a sense of deprofessionalization in the community.