The Shift Project, a joint project at Harvard Kennedy School and UCSF, examines the nature and consequences of precarious employment in the service sector with a focus on how policymakers and firms can improve job quality. Since 2016, Shift has surveyed over 100,000 workers using an innovative recruitment method to target employees at the largest chain retail and food-service firms. We ask workers across the United States about their working conditions, economic security, health, and family life. Our national dataset sheds light on the nature of precarious employment practices — with a special focus on work schedules — around the country and within and across large firms, as well as the consequences of these employment practices for worker and family economic security, health, and wellbeing. The consequences we examine range from a parent’s ability to secure childcare when they are on call, to the impact of a cancelled shift on a worker’s psychological distress. We also bring our data to bear to produce research briefs highlighting workers’ experiences of precarious employment in specific states and localities and we deploy our data for policy evaluation studies, such as estimating the effect of secure scheduling ordinances in Seattle and of paid sick leave in Washington State. Finally, we use matched employer-employee data to describe between-firm variation in job quality and highlight employers who “take the high road” in their approach to job quality.