The present study, framed by complex dynamic systems theory (de Bot et al., 2007; Larsen-Freeman & Cameron, 2008), explores the relationship between co-adaptation and journaling. Primarily viewed as a theoretical, explanatory mechanism, co-adaptation—a process describing how components of a dynamic system (e.g., a classroom) interact and reorganize their behavior in mutually influential ways to solve local problems (e.g., communication)—also holds promise as a teaching tool for developing L2 academic literacy (Fogal et al., 2020). To investigate this underexamined possibility, the present classroom-based study engages with journaling as a form of educational practice for academic literacy development. This study examines context-related affordances and an iterative series of daily journal entries and instructor reflections through a thematic analysis in line with design-based research and based on Baba (2020). Findings highlight how co-adaptation through journaling can help describe developmental processes and assist teachers and learners in developing academic literacy practices. This work contributes to discussions about how to conceptualize and operationalize classrooms as co-adaptive and relational spaces and invites instructors to reimagine journaling and journaling feedback as a resource for engagement and co-adaptation in the teaching-learning environment.