I'm looking for recommendations on connecting to a Neptune cluster in AWS from a VPC that the Neptune cluster does not exist in. I'm thinking if I have a transit gateway as an intermediary bridge between the 2 VPCs I'll be able to proxy the connection through so connectivity is successful.
I need this for reads and writes. Is this an acceptable approach for a production-grade env? In addition, I'm expecting to hit the REST endpoint I think from a client-based application once the request gets into the VPC containing the Neptune cluster.
Transit Gateway would be a fine production approach here. VPC Peering between the two VPCs would also work well for production systems. There is also a reference architecture for using a Network Load Balancer or Application Load Balancer. If you have issues, you want to make sure your security groups and routing tables are configured correctly. Sending an HTTPS request to the Status endpoint is the easiest way to test your connectivity to Neptune.