Hey @Jason Bosco is what you guys call

Search Delivery Network

essentially the same as setting up high availability clusters?

Search Delivery Network (SDN) is more like a CDN, where nodes are provisioned in different geo regions and the request is served from the node that's closest to the user. SDN also gives you High Availability automatically because there are multiple nodes at play. But you can also have multiple nodes in a single geo region, which would be a non-SDN HA cluster

How does the client chose among the available nodes in an SDN?

That logic is on the Typesense Cloud side. When you specify a

nearest_node

key in the client, all requests are sent by the client to that endpoint.

So a client needs to connect first to a TS cloud server which then gives it the closest TS node geographically based on their IP/DNS?

No, the IP address returned by the DNS lookup for the SDN endpoint that Typesense Cloud gives you will return the IP address of the node that's closest to the user