ABSTRACT The present study investigates longitudinal relationships between job insecurity and a set of work, career, and life outcomes. Using an integrative theoretical framework that combines the principles of conservation of resources and sustainable career development, we aim to unravel the scope and dynamics of stressor-strain pathways that undermine employee well-being in these domains. To that end, latent curve modelling with structured residuals was performed on a large heterogeneous sample (N = 1134) of individuals living and working in Switzerland. Based on seven annual measurement points, the results revealed yearly within-person dynamics through which job insecurity may hinder sustainable well-being in different areas of life. Furthermore, our findings allow for contrasting short-term (yearly) versus long-term (7-year) effects. They uncover potential protective mechanisms through which between-person differences in the initial levels of sustainable well-being resources might mitigate the risks of being increasingly exposed to job insecurity over time, as reflected in within-person growth patterns. Research, policy, and practical implications are discussed based on these findings.