INTRODUCTION: Decision-makers initially had limited data to inform their policy responses to the COVID-19 pandemic. The research community developed several online databases to track cases, deaths, and hospitalizations; however, a major deficiency was the lack of detailed information on how health systems were responding to the pandemic and how they would need to be transformed going forward. APPROACH: In an effort to fill this information gap, in March 2020, the European Observatory on Health Systems and Policies, the WHO European Regional Office and the European Commission created the COVID-19 Health System Response Monitor (HSRM) to collect and organise up-to-date information on how health systems, mainly in the WHO European Region, were responding to the COVID-19 pandemic. FINDINGS: The HSRM analysis and broader Observatory work on COVID-19 shone light on a range of health system challenges and weaknesses and catalogued policy options countries put in place during the pandemic to address these. Countries prioritised policies on investing in public health, supporting the workforce, maintaining financial stability, and strengthening governance in their response to COVID-19. OUTLOOK: COVID-19 is likely to continue to impact health systems for the foreseeable future; the ability to cope with this pressure, and other shocks, depends on having good information on what other countries have done so that health systems develop adequate policy options. In support of this, the country information on the COVID-19 HSRM will remain available as a repository to inform decision makers on options for actions and possible measures against COVID-19 and other public health emergencies. Building on its previous work on health systems resilience, the European Observatory on Health Systems and Policies will sustain its focus on analysing key issues related to the recovery from the pandemic and making health systems more resilient. This includes policy knowledge transfer between countries and systematic resilience testing, aiming at contributing to an improved understanding of health system response, recovery, and preparedness. CONTRIBUTION TO THE LITERATURE IN NON-TECHNICAL LANGUAGE: The COVID-19 Health System Response Monitor (HSRM) was the first database in the WHO European Region to collect and organise up-to-date information on how health systems were responding to the COVID-19 pandemic. The HSRM provides a repository of policies which can be used to inform decision makers in health and other policy domains on options for action and possible measures against COVID-19 and other public health emergencies. This initiative proved particularly valuable, especially during the early phases of the pandemic, when there was limited information for countries to draw on as they formulated their own policy response to the pandemic. Our perspectives paper highlights some key challenges within health systems that the HSRM was able to identify during the pandemic and considers policy options countries put in place in response. Our research contributes to literature on emergency responses and recovery, health systems performance assessment, particularly health system resilience, and showcases the Observatory experience on how to design such a data collection tool, as well as how to leverage its findings to support cross-country learning.