BACKGROUND: Coronavirus disease 2019 (COVID-19) has resulted in over 2 million deaths globally. The experience in Australia presents an opportunity to study contrasting responses to the COVID-19 health system shock. We adapted the Hanefeld et al framework for health systems shocks to create the COVID-19 System Shock Framework (CSSF). This framework enabled us to assess innovations and changes created through COVID-19 at the Sydney Children's Hospitals Network (SCHN), the largest provider of children's health services in the Southern hemisphere. METHODS: We used ethnographic methods, guided by the CSSF, to map innovations and initiatives implemented across SCHN during the pandemic. An embedded field researcher shadowed members of the emergency operations centre (EOC) for nine months. We also reviewed clinic and policy documents pertinent to SCHN's response to COVID-19 and conducted interviews and focus groups with stakeholders, including clinical directors, project managers, frontline clinicians, and other personnel involved in implementing innovations across SCHN. RESULTS: The CSSF captured SCHN's complex response to the pandemic. Responses included a COVID-19 assessment clinic, inpatient and infectious disease management services, redeploying and managing a workforce working from home, cohesive communication initiatives, and remote delivery of care, all enabled by a dedicated COVID-19 fund. The health system values that shaped SCHN's response to the pandemic included principles of equity of healthcare delivery, holistic and integrated models of care, and supporting workforce wellbeing. SCHN's resilience was enabled by innovation fostered through a non-hierarchical governance structure and responsiveness to emerging challenges balanced with a singular vision. CONCLUSION: Using the CSSF, we found that SCHN's ability to innovate was key to ensuring its resilience during the pandemic.