Strong, resilient health systems are imperative to the health and wellbeing of people in any country. A health system consists of multiple layers of institutions and individuals, a complex interplay between stakeholders in academia, healthcare, public health, politics and economics, working together to cater for the health needs of their community.Health systems globally face various challenges, from lack of access to medicines and vaccines to emerging health inequalities. This led the SheffWHO Organizing Committee to choose ‘’Building Back Better: Strengthening Health Systems’’ as the theme for the 2021 Simulation.