The current study examines the professional learning trajectory of six teacher candidates in their first school placement. They were participants in a redesigned practicum component guided by sociocultural learning theory. Data were collected through the use of an abbreviated form of the Development Work Research (Engestrom) during the weekly meeting of candidates, cooperating teachers and university practicum supervisor. An analysis of field notes and transcripts of the conversations among participants evidences how performing tasks authentic to teaching and the mediating tools used by cooperating teachers and supervisors moved candidates from a focus on their teaching to a concern for how much their students were learning. These findings exemplify the importance of designing and implementing the initial practicum course as a space that enables teacher candidates to work on authentic teaching tasks, with the joint mediation of peers, cooperating teacher and university tutor, to strengthen professional agency.Este estudio examina la trayectoria de aprendizaje profesional de seis estudiantes de pedagogia participantes en un programa de innovacion en la practica inicial. La innovacion se sustento en el enfoque sociocultural de aprendizaje. Se realizo una version abreviada de investigacion evolutiva en el trabajo (Engestrom) en los talleres de practica semanal donde ellos participaron junto con tutores universitarios, profesora mentora e investigadora Notas de campo y analisis de las conversaciones evidenciaron como la incorporacion de tareas autenticas a la labor docente y herramientas de mediacion con voces de la academia y del centro escolar, movilizaron a los practicantes desde un foco en su ensenanza hacia un foco en el aprendizaje de sus estudiantes. Estos resultados ejemplifican la importancia de construir nuevas configuraciones para el curriculo de la practica inicial que enfrenten a candidatos a tareas autenticas al quehacer docente, con mediacion conjunta de pares, profesores mentores y tutores, que fortalezcan su agencia profesional.