When container platforms grow from a dozen services to over a hundred, operational weight shifts. No longer "how do we run a container?" but "how do we consistently, cheaply, safely run hundreds?" Three pains strike simultaneously. Scheduling (when traffic surges, how fast and what instance type do we spin?), drift (who deployed what and does actual state match intent?), cost (peak-capacity nodes sit idle at night). Today: realistic org with 100+ microservices, 100k peak RPS, Seoul·Tokyo Active-Active, "20% cost cut YoY" pressure. Karpenter·GitOps·Pod Identity·Container Insights·Graviton/Spot solve all three, grounded in scheduling theory and declarative-system thinking.