We characterize what features make supply chains more resilient. Using new data on the universe of firm-to-firm transactions from an Indian state, we identify firms with larger supplier risk following the Covid-19 lockdowns. Using an event-study design we find firms with suppliers in strict-lockdown districts experienced 4.5pp higher separation rates (a 15% increase relative to baseline). We study which characteristics increase supply-chain resilience. Firms that buy more complex products, with fewer available suppliers, are less likely to break links. We explore how firms change post-shock supplier composition. Firms with higher supplier risk form new links with larger and better-connected suppliers.