COVID-19 has created many constraint-related challenges for humans in general and organisations in particular. Specifically, businesses that require physical contact, such as mobility providers, have been severely impacted by the crisis. This paper reveals how mobility platforms and their ecosystem of actors have adapted faster than their non-platform competitors to become resilient. Whereas current research on resilience explicitly deals with the concept of organisational resilience, community resilience, or IT resilience, socio-technical characteristics of digital platforms have not been investigated. We build on a case survey approach, including heterogeneous qualitative evidence of 266 actions of 171 analysed mobility platforms. The results show five archetypes of how mobility platforms leverage their platform-based nature and the ecosystem to build resilience. Based on this, we develop the concept of platform ecosystem resilience as leveraging socio-technical factors of digital platforms and ecosystems frugally to design, deploy and use situation-specific responses to prepare for, endure and adapt by capturing new opportunities and engaging in transformative activities to cope with exogenous shocks and become resilient for future disruptions. Our results emphasise the importance of platform ecosystems for practitioners and policy planners to develop the "new normal" rather than resuming existing practices.