Provisioning a key in a VPC private subnet begins with strict access control. Generate the key from a secure, centralized store. Never expose it to a public endpoint. Store it in a KMS service set to enforce least privilege. Every step must maintain encrypted transit and at-rest security.
The private subnet isolates your workloads from the internet. Configure its route tables with no default 0.0.0.0/0 path. Use NAT gateways only if outbound traffic is required, and lock those flows down with security groups. This ensures the proxy sits firmly inside a trusted perimeter.
Deploying the proxy in a VPC private subnet requires clear network mapping. Place the proxy in an availability zone nearest the backend systems it will reach. Bind the proxy to an elastic network interface in the subnet. Confirm DNS resolution within the VPC is functional. Without it, service discovery breaks fast.
Scale considerations mean using auto-scaling groups tied to health checks that test real connectivity, not just instance status. When provisioning the proxy, update its configuration via a secure pipeline that injects the key into environment variables at deploy time. No manual edits. No keys in source control.