Explore the networking journey of The New York Times as they built multi-tenant Kubernetes clusters to host thousands of containers. Learn about the critical decision to implement Cilium for enhanced networking performance, identity-based security, and application-aware visibility in cloud-native workloads running on EKS. Discover the requirements that led to choosing Cilium, the design tradeoffs and security considerations made, and the challenges faced before and after production deployment. Gain insights into debugging critical production issues, including contributions to the Cilium upstream codebase. This 28-minute conference talk provides valuable lessons for those looking to optimize their own Cilium implementation and secure multi-tenant runtime environments at scale.