You must design a Shared VPC so Production and Staging communicate only over specific networks and the network/security team strictly controls route exposure. Following Google best practices, how should you architect this?

The correct approach is to create a single VPC in the host project and selectively share individual subnets with service projects. This aligns with Google best practices for Shared VPC, allowing granular control over network exposure. By sharing only specific subnets, you limit the communication paths between Production and Staging environments, meeting the requirement for communication only over specific networks. The network/security team maintains strict control over route exposure because the host project administrator manages subnet sharing. Incorrect options: Creating two shared VPCs within the host project and peering them is not a standard or efficient way to manage granular subnet sharing within a single Shared VPC setup. Peering is typically used for connecting distinct VPC networks. Creating two shared VPCs within the host project and using Cloud VPN/Cloud Router with Flexible Route Advertisement (FRA) is overly complex and unnecessary for managing communication between environments within the same Shared VPC. FRA is more relevant for hybrid connectivity or complex multi-VPC routing scenarios. Creating two shared VPCs within the service project is fundamentally incorrect; Shared VPCs are defined at the host project level, and service projects consume resources from the host project's VPC.