Kong Gateway upstream entity relationships define how client requests route through plugins, services, and load-balanced targets with health checks and mTLS. Requests flow from Client through Route and Route-level Plugins to Service, where Service-level Plugins apply before forwarding to Upstream. The Upstream entity manages load balancing across multiple Targets (A, B, C) with integrated health checks and certificate-based mTLS authentication. This architecture demonstrates Kong's layered plugin system and upstream load balancing for resilient API traffic management. Fork this diagram on Diagrams.so to customize routing policies, add additional targets, or document your Kong deployment topology.