Introduction to Kubernetes and Containerization
Why Containers Won
Containers package an application with its dependencies into an immutable artefact that runs the same way on a laptop, in CI, and in production. They're lighter than VMs, faster to start, and scriptable from end to end. Docker made them popular; OCI standardised them.
What Kubernetes Actually Does
Kubernetes is a container orchestrator. Given a desired state ("run 6 copies of this service, behind a load balancer, restart any that crash"), it makes the cluster match.
Core building blocks:
- Pod — one or more containers that share a network and lifecycle
- Deployment — declarative spec for replicated pods
- Service — stable network endpoint for a set of pods
- Ingress — HTTP routing into the cluster
- ConfigMap / Secret — configuration injection
- PersistentVolume — durable storage outside the pod lifecycle
What It Buys You
- Self-healing — failed pods are replaced automatically
- Horizontal scaling — by CPU, memory, or custom metrics
- Rolling deploys with health checks and rollback
- A standard interface across cloud providers and on-prem
- A rich ecosystem (Helm, Istio, ArgoCD, Prometheus)
What It Costs You
- Learning curve. The conceptual surface is large.
- Operational overhead. Day-2 ops (upgrades, security, scaling) is real work.
- Failure-mode complexity. When things break, debugging spans many layers.
- Cost. Control planes, observability, and the experts to run them aren't free.
When to Skip Kubernetes
If you're a small team running a handful of services, managed alternatives are usually better:
- Cloud Run / App Runner / Container Apps — containers without the orchestration tax
- Serverless — for event-driven workloads
- Managed PaaS (Vercel, Railway, Fly.io) — for web apps that don't need cluster-level control
When to Embrace It
- Large fleets of services with shared platform needs
- Multi-cloud or hybrid deployments
- Heavy stateful workloads with custom scheduling
- Mature platform teams ready to operate it
The Bottom Line
Kubernetes is a brilliant fit for the problems it was designed for and a heavy tax for the problems it wasn't. Match the tool to the problem.
*We design and run Kubernetes platforms — and we'll tell you honestly when you don't need one. Get in touch →*