The Uptime Engineer
👋 Hi, I am Yoshik Karnawat
Don’t scroll past, this week’s 180 second read might just save you hours at work.
Facts
Helm has over 1,800 production-ready charts in its official repository. The largest Kubernetes package ecosystem
Kustomize ships native in kubectl since Kubernetes 1.14
73% of teams using both tools report using Helm for third-party apps and Kustomize for internal customization
The Kubernetes package ecosystem grew from 100 to 800+ packages in just 3 years
Teams overengineer Helm charts with 50+ values for a simple app.
Or they copy-paste repetitive Kustomize overlays that should've been templated.
Engineers are often confused.
Here's what you need to know.
How they work
Helm = Package Manager + Templating Engine
Helm packages Kubernetes apps into versioned "charts" with Go templates.
You define variables in values.yaml, and Helm renders them into final manifests.
Think of it like npm for Kubernetes except it also handles deployments, rollbacks, and dependency management.
Kustomize = Patch-Based Configuration
Kustomize uses a "base + overlays" approach.
You maintain one base configuration, then create overlays that specify only what changes per environment.
No templating. No variables. Just plain YAML with patches applied on top.
The real differences
Aspect | Helm | Kustomize |
|---|---|---|
Approach | Templating with Go syntax | Overlays on raw YAML |
Native kubectl | No (requires Helm CLI) | Yes (built into kubectl) |
Packaging | Yes (versioned charts) | No |
Rollbacks | Built-in with release history | Manual |
Complexity | High (template logic gets messy) | Low (just YAML patches) |
Community | 1,800+ prebuilt charts | No chart ecosystem |
Learning Curve | Steep (must learn Go templating) | Shallow (if you know YAML, you're ready) |
When to use Helm
Deploying third-party applications
Helm's chart repository has prebuilt packages for databases, monitoring tools, ingress controllers.
Why write YAML from scratch?
Complex applications with dependencies
If your app requires multiple services with interdependencies, Helm's dependency management saves you from coordination hell.
You need versioning and rollbacks
Helm tracks every release.
One command rolls back to any previous version.
Distributing applications across teams
If you're building internal platforms, Helm lets you package apps once and let other teams deploy with custom values.
When to use Kustomize
Multi-environment deployments
Same app, different configs per environment?
Kustomize's overlays prevent config duplication.
Development environments might need reduced resource limits to save costs, while production needs enhanced security settings and monitoring.
You want readable, debuggable manifests
No templating logic means no debugging cryptic Go syntax.
What you see is what you deploy.
GitOps workflows
Kustomize integrates natively with ArgoCD and Flux.
No extra tooling needed.
Modifying third-party Helm charts without forking
Deploy a Helm chart, then use Kustomize to patch it, add labels, change resource limits, inject secrets.
The strategy most production teams use
Helm for packaging. Kustomize for customization.
Use Helm to deploy the application (handles dependencies, versioning, lifecycle).
Use Kustomize overlays to apply environment-specific changes (namespaces, resource limits, security policies).
Example workflow:
helm template myapp ./chart > base.yaml kustomize build overlays/production | kubectl apply -f -This gives you Helm's package management plus Kustomize's transparency.