3 — ReplicaSets

Kubernetes

A book-shaped table of contents for Kubernetes: cloud-native foundations, the CKAD/CKA/CKS certification tracks, control-plane internals, platform tooling, multi-cluster architecture, and MAANG-level system design and interview prep — cross-linking the existing Prometheus, Observability, and Platform Engineering chapters instead of duplicating them.

2 — Labels, Selectors & Annotations

Labels are indexed and queryable for selection and grouping; annotations hold non-identifying metadata the scheduler never selects on.

8 — Namespaces

Namespaces partition names and quota, not network or security — RBAC and NetworkPolicy have to be added explicitly, isolation is never implied by the namespace boundary alone.

1 — Pods

Why a Pod, not a container, is the atomic unit of scheduling — containers sharing a Pod share network namespace and IPC but never share a lifecycle.

9 — Resource Management (Requests, Limits, QoS)

The scheduler only reads requests, never limits — the requests-to-limits ratio instead decides the pod's QoS class, which is what actually governs eviction order under node pressure.