I think just like any other server, but with fewer things to set up (HTTPS, certificates, etc). We also have an ingress controller in the works: https://github.com/caddyserver/ingress

(Not a Kubernetes user, so my answer is probably not the best.)

Caddy at its simplest form is an HTTP server. So you could use it to front end your application that otherwise isn't well suited for taking direct HTTP requests. Caddy would bring you other features like TLS support.

However I think in K8s world Caddy would make the most sense as an Ingress Controller. There is even a project as such: https://github.com/caddyserver/ingress

All traffic would terminate first at Caddy. Handling TLS, HTTP1/2/3, etc. Then passing it back to your application service/pod.

In addition to what others have said, I think it’s a handy option for a lightweight http backend or proxy when you need it to glue something together. For example, quickly fronting an s3 bucket, or serving static content generated by another container in the same pod, etc.