Lesson Study (LS), as a training process for preservice teachers (PT), emphasizes reflection and the continuous improvement of teaching practices, cooperative and collaborative work, and the mastery of disciplinary content. This research aimed to evaluate the contribution of LS to the training process of PTs. The study employs a qualitative methodology and follows a case study design, involving the Federal University of Campina Grande (UFCG-Brazil), the National University of Education (UNAE-Ecuador), and the University of Brasilia (UNB-Brazil) as participants in Mixed Learning Communities (MLCs) within virtual environments. This experience fostered knowledge management in intercultural contexts, the dialogue of knowledge systems, the revision of diverse curricular content, and the strengthening of connections between disciplinary and interdisciplinary knowledge. The collaborative and reflective engagement within the MLCs enabled the iterative development of lesson plans through discussions and consultations with researchers. Ultimately, determining what to teach and how to teach involves a systematic process grounded in collective efforts tailored to the needs of students.