What is the difference between using Kustomize and Tekton for deployment?
To me it looks like Kustomize is a lightweight CI/CD client developer tool where you manually go in and do your CI/CD, where Tekton is automated CI/CD running within Kubernetes?
Kustomize is a tool for overriding (instead of templating) your Kubernetes manifest files. It it now built-in in kubectl with kubectl apply -k.
Tekton is a project for creating Kubernetes Custom Resources for building CICD pipelines of tasks on Kubernetes. One of the tasks in a pipeline can be an image with kubectl that apply the changes using Kustomize (kubectl apply -k).