Kubernetes (K8s)
Also called K8s.
An open source platform that runs and manages containers across a group of machines: starting them, restarting them, scaling them and routing traffic to them.
Last updated
What it is.
You tell Kubernetes what you want, such as five copies of this container with this much memory, reachable at this address. It works out where to run them, restarts any that crash, replaces machines that fail and rolls out new versions. Google open sourced the project in 2014.
Every major cloud offers managed Kubernetes, where the provider runs the control layer and you manage the workloads. Simpler managed container services and serverless platforms cover many apps without it.
Why it matters
Kubernetes gives a standard way to run many services reliably and portably across clouds. It is also complex: networking, security, upgrades and cost control all need skilled people. For a small product it can be more platform than the app needs.
In a product build
We use Kubernetes when there are many services, portability needs or special workloads, and prefer managed container services for simpler apps. When we use it, the cluster and its workloads are defined with infrastructure as code, with resource limits and autoscaling set per service.
Common mistakes.
- 01
Adopting it for a single app because it is popular.
- 02
No resource limits, so one service can starve the others.
- 03
Falling behind on version upgrades until the managed service forces them.
Read the official text.
Primary sources this definition is based on.
- Kubernetes documentation, Overviewchecked 2026-10-25
Related terms.
- Container (software)A package that holds an application and everything it needs to run, isolated from other software on the same machine.
- AutoscalingAutomatically adding or removing computing capacity, such as servers or containers, as the load on a system goes up or down.
- MicroservicesA way of building an application as many small services, each owning one job and its own data, deployed independently.
- Infrastructure as code (IaC)Defining servers, networks, databases and other cloud resources in code files that are versioned and applied automatically, instead of setting them up by hand.
- Load balancerA service that spreads incoming traffic across several servers, and stops sending traffic to any that fail their health checks.
