This chapter provides a comprehensive exploration of the intricate interplay between career development and well-being across the life cycle, spanning from childhood through adulthood. Drawing from the life-long framework of life design, which emphasizes the development of the vocational self, the chapter considers individual and contextual influences, non-linear dynamic processes, and individual psychological and social patterns. It delves into how these multidimensional factors shape career development processes at various life stages, encompassing childhood, adolescence, and young adulthood transitions from school to work, school to university, and university to work. Through a review and critical analysis of empirical research, the chapter elucidates the diverse mechanisms underlying successful and sustainable career development and the enhancement of well-being at various life stages, suggesting good practices to encourage career development. The chapter offers valuable insights into how support individuals in navigating their career trajectories and fostering holistic well-being across the lifespan.