Sealos Cloud supports 87,000 users and thousands of concurrent app deployments on shared Kubernetes clusters. We hit hard limits with Nginx Ingress—reload instability, high resource usage, and poor long-connection handling. This post details why we moved to an Envoy-based gateway (Higress), what went wrong with other solutions (APISIX, Cilium, Envoy Gateway), and what it really takes to support massive multi-tenancy in public cloud environments.