Any SpiceDB node can handle an incoming request, so for incoming traffic you can set up your favorite load balancer
Peer traffic (between spicedb nodes) has a couple of options. The easiest is to run on kubernetes and use the service for peer discovery (example here: https://github.com/authzed/spicedb/blob/b3a05f8dcd546910c60ad84b7cc83eb642a4f650/examples/k8s/example.yaml#L117-L118)
If you're not running on kube, we do have provisional support for XDS for peer discovery (you'd use