AWS Certified Advanced Networking – Specialty (ANS-C01)Network DesignMedium
A global software company is deploying a new multi-tenant SaaS application. Each customer's environment is isolated in its own AWS account and VPC. The SaaS application, hosted in a central 'Provider' VPC, needs to offer private and secure access to its services for hundreds of customer VPCs without exposing the services to the public internet or requiring VPC peering. The solution must scale efficiently as new customers are onboarded. Which AWS networking service should the company use?
- AAWS Transit Gateway with inter-VPC routing
- BVPC Peering with cross-account access
- CAWS PrivateLink (VPC Endpoint Service)
- DAWS Global Accelerator
Show answer & explanationAnswer & explanation
Correct answer: C. AWS PrivateLink (VPC Endpoint Service)
AWS PrivateLink, through the creation of a VPC Endpoint Service by the SaaS provider, allows consumers (customer VPCs) to privately access the SaaS application using interface VPC endpoints. This avoids exposing the service to the public internet, eliminates complex VPC peering, and scales efficiently for a multi-tenant architecture across many accounts.
Why the other options are wrong
- A. AWS Transit Gateway can connect many VPCs, but it's primarily for routing traffic between VPCs you own. For a SaaS provider offering services to external customer VPCs, PrivateLink is more appropriate for private service exposure without routing customer traffic through the provider's entire network.
- B. VPC peering is not scalable for hundreds of customer VPCs and requires explicit configuration for each pair, leading to a management nightmare.
- D. AWS Global Accelerator improves performance by routing traffic over the AWS global network but still uses public endpoints and doesn't provide the private, isolated access required by the security mandate.
AWS PrivateLink (VPC Endpoint Service)
A technology that enables private connectivity between VPCs and AWS services, other AWS accounts, and on-premises applications, without exposing data to the public internet.
- Provider creates a VPC Endpoint Service.
- Consumers create Interface VPC Endpoints to access the service.
- No public IP addresses, NAT gateways, or internet gateways required.
- Ideal for SaaS offerings and private service consumption.
Memory trick: PrivateLink is the private 'link' for your SaaS customers.