The balance between work, family and private life is being disrupted by profound socio-economic, demographic and political changes that are reconfiguring individual life courses and calling for new and ambitious research. Understanding these changes is crucial for designing appropriate public and corporate policies. Given the lack of recent data on these issues, in 2018 we formed a team within INED's Economic Demography Unit to develop a large-scale statistical survey, the Longitudinal Survey Families and Employers (FamEmp). It consists of two parts, one with more than 35,000 individuals to be interviewed in 2024, 2027 and 2030, and the other with their employers, 12,000 establishments with 10 or more employees. The survey data will be linked to administrative data. The aim of the project is to use these unique data to measure current work-life balance conditions, their rapid evolution and their impact on economic, social and gender inequalities throughout the life course. The first axis of the project will take stock of the current state of work-life balance, both in general and in specific work and family configurations. In particular, the impact of new forms of employment (short-term contracts, self-employment) and work (teleworking) will be analysed. Attention will also be paid to specific family configurations, such as those following separation (shared custody, stepparents and single-parent families), which are at increase. The situation of family carers for people with disabilities or loss of autonomy, which raises new issues of reconciliation, will also be examined. In the second axis, the longitudinal dimension of the survey will be used to observe changes over the life cycle, with a particular focus on gender inequalities. We will identify turning points in careers, the interactions between family and work events and the causal mechanisms at work. In particular, the impact of childbirth on gender inequalities in careers will be better understood by examining the different career mobility of women and men during their working lives and the trade-offs within couples. In a third axis, the employer survey will allow us to examine companies' practices and assess whether the measures they take are likely to facilitate their employees' work-life balance. In the project, we will mobilise a wide range of quantitative analysis methods. The WorkLiB project responds to one of the major challenges of our time: how to better share time across life, within couples and according to gender. It will provide answers for public authorities and companies to develop targeted policies to improve the well-being of individuals (parents, children, carers) and promote equality between women and men. As part of an open science approach, the results will be widely disseminated and the data will be made available to the scientific community.