This study examines the development of reflective practice among students on a four-year work-based Software Engineering program. Using two established models of reflection - Boud et al.'s Model of Reflective Process and Bain et al.'s 5R Framework for Reflection - we analyse a series of reflective assignments submitted by students over four years. Our longitudinal analysis reveals clear trends in how students' reflective abilities evolve over the course of the program. We find that more sophisticated forms of reflection, such as integration of knowledge, appropriation of skills, and reconstruction of practice, increase markedly in prevalence in later years. The complementary nature of workplace experience and university study is highlighted in students' reflections, demonstrating a key benefit of the work-based learning approach. By the final year, all students demonstrate the ability to reconstruct their experiences to inform future practice. Our findings provide insight into how reflective practice develops in Software Engineering education and suggest potential value in incorporating more structured reflection into traditional degree programs. The study also reveals instances of meta-reflection, where students reflect on the value of reflection itself, indicating a deep engagement with the reflective process. While acknowledging limitations, this work offers a unique longitudinal perspective on the development of reflective practice in work-based Software Engineering education.