This working paper aims to synthesize the set of techniques for systematizing and analyzing diachronic and/or longitudinal qualitative data, deepening the technique of constructing Life Lines, using the presentation and description of an experience of application. Based on biographical interviews conducted as part of a master's thesis in Sociology, this working paper sought to demonstrate how Life Lines make it possible to systematize and visualize complex biographical sequences, crossing dimensions such as residential, occupational and marital paths. The text contextualizes the Biographical Method and its strands (demographic, historical and anthropological), highlighting the potential of Life Lines to integrate mixed methodological approaches. It discusses the stages involved in constructing the lines, the challenges of making them operational and the analytical and comparative gains that this type of instrument offers. Despite the inferential limitations, the empirical results show the usefulness of this instrument in contemporary sociological research, contributing to the visualization of biographical patterns and the understanding of the interactions between individual agency and social structure.