| Question | Helm | Kustomize |
|---|---|---|
| Input | Go templates plus values | Plain, valid YAML |
| Environment differences | Values files | Overlays with patches |
| Packaging and versioning | Charts in repositories | None; Git 1,932 is the package |
| Lifecycle ordering | Hooks and weights | Kind order only (Namespaces first) |
Helm suits software others install, where the author decides what is configurable; Kustomize suits manifests you own, with nothing hidden behind a value nobody exposed. Its weakness: a JSON patch path such as /spec/listeners/1 silently edits the wrong entry once the base reorders the list. Many teams use Helm for third-party software and Kustomize for their own, with Argo CD 126 or Flux 213,041 (GitOps with Argo CD) rendering both.