Allow Cloud Run and Cloud Functions (serverless) to access microservices in a private subnet with low volume and full connectivity between serverless and microservices while minimizing cost.

A single Serverless VPC Access connector is the most cost-effective and efficient solution for this scenario. It allows multiple serverless services (Cloud Run, Cloud Functions) to connect to resources within your VPC's private subnet using a shared internal IP address, minimizing the number of connectors needed and centralizing management. This provides full connectivity with low overhead, aligning with the "low volume" and "minimizing cost" requirements. Deploying serverless services into a serverless VPC and peering it to the existing VPC is not a standard or direct deployment model for Cloud Run/Functions. Creating a separate connector for each service would increase cost and management complexity unnecessarily. Deploying serverless services directly into an existing VPC is not possible; serverless services run in Google-managed environments and require a connector to access private VPC resources.