We investigate the resilience of the South African banking system using a dynamic agent-based model and the DebtRank algorithm. This approach enables us to identify each bank’s importance and vulnerability in the interbank network and is not limited to listed banks, as previous studies were. We find that larger banks are more systemically important, but a bank’s interbank-lending-to-equity multiple is significantly correlated with its vulnerability. Our research offers policymakers a direct and practical indicator for improved monitoring of financial stability.