The answer is to create an S3 gateway endpoint and a Secrets Manager interface endpoint with private DNS enabled. This is correct because VPC Gateway Endpoints use route table entries to reach S3 over the AWS backbone, while Interface Endpoints assign a private IP to Secrets Manager, allowing traffic to stay entirely within the AWS network. Together, they eliminate internet exposure for those calls and remove the dependency on a NAT gateway, directly reducing costs. On the SAA-C03 exam, this scenario tests your understanding of when to use each endpoint type: gateway endpoints work only for S3 and DynamoDB, while interface endpoints support all other AWS services like Secrets Manager. A common trap is assuming both services can use the same endpoint type, but S3 requires a gateway endpoint for cost efficiency, whereas Secrets Manager needs an interface endpoint with private DNS to resolve its public hostname privately. Memory tip: “Gateway for S3, Interface for the rest” helps you quickly match the service to the correct endpoint.
SAA-C03 Design Secure Architectures Practice Question
This SAA-C03 practice question tests your understanding of design secure architectures. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Exhibit
Private subnet route table rtb-priv:
- 10.0.0.0/16 local
- 0.0.0.0/0 -> nat-0a12bc34
Application logs:
2026-04-20T10:14:11Z ERROR could not reach https://secretsmanager.us-east-1.amazonaws.com:443
2026-04-20T10:14:11Z ERROR timeout after 30s while downloading s3://company-artifacts-builds
Finance note:
"NAT data processing charges increased 42% last month."
Based on the exhibit, a workload in private subnets must reach only Amazon S3 and AWS Secrets Manager. The team wants to eliminate internet exposure for those calls and reduce NAT gateway charges. What change should be made?
Private subnet route table rtb-priv:
- 10.0.0.0/16 local
- 0.0.0.0/0 -> nat-0a12bc34
Application logs:
2026-04-20T10:14:11Z ERROR could not reach https://secretsmanager.us-east-1.amazonaws.com:443
2026-04-20T10:14:11Z ERROR timeout after 30s while downloading s3://company-artifacts-builds
Finance note:
"NAT data processing charges increased 42% last month."
A
Move the instances into a public subnet and restrict inbound access with security groups.
Why wrong: That would expose the workload to the internet, which directly violates the private connectivity requirement. Security groups do not replace the need for private network design.
B
Add a NAT instance and disable the managed NAT gateway to lower cost.
Why wrong: A NAT instance still sends traffic through an internet path and adds operational overhead. It does not remove public exposure for AWS service calls.
C
Create an S3 gateway endpoint and a Secrets Manager interface endpoint with private DNS, then remove NAT dependency for those service calls.
S3 is best reached through a gateway VPC endpoint, while Secrets Manager requires an interface endpoint. With private DNS enabled, the application can resolve and reach those services without leaving AWS private networking. This removes the need for NAT traffic for those calls, cuts cost, and keeps service access off the public internet.
D
Use VPC peering to a shared services VPC and route all AWS service traffic through that VPC.
Why wrong: VPC peering does not provide native endpoints for AWS managed services and does not eliminate the internet path for those service APIs. It also adds routing complexity without solving the core problem.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Create an S3 gateway endpoint and a Secrets Manager interface endpoint with private DNS, then remove NAT dependency for those service calls.
Option C is correct because VPC Gateway Endpoints (for S3) and Interface Endpoints (for Secrets Manager) allow private subnet instances to access these services over the AWS network without traversing the internet or a NAT gateway. Enabling private DNS on the interface endpoint ensures that the default Secrets Manager DNS name resolves to the endpoint's private IP, eliminating the need for a NAT gateway for those calls and reducing costs.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Move the instances into a public subnet and restrict inbound access with security groups.
Why it's wrong here
That would expose the workload to the internet, which directly violates the private connectivity requirement. Security groups do not replace the need for private network design.
✗
Add a NAT instance and disable the managed NAT gateway to lower cost.
Why it's wrong here
A NAT instance still sends traffic through an internet path and adds operational overhead. It does not remove public exposure for AWS service calls.
✓
Create an S3 gateway endpoint and a Secrets Manager interface endpoint with private DNS, then remove NAT dependency for those service calls.
Why this is correct
S3 is best reached through a gateway VPC endpoint, while Secrets Manager requires an interface endpoint. With private DNS enabled, the application can resolve and reach those services without leaving AWS private networking. This removes the need for NAT traffic for those calls, cuts cost, and keeps service access off the public internet.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use VPC peering to a shared services VPC and route all AWS service traffic through that VPC.
Why it's wrong here
VPC peering does not provide native endpoints for AWS managed services and does not eliminate the internet path for those service APIs. It also adds routing complexity without solving the core problem.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse Gateway Endpoints (for S3 and DynamoDB) with Interface Endpoints (for most other AWS services), and may incorrectly assume a single endpoint type works for all services, or that a NAT gateway is still required for private subnet traffic to AWS services.
Detailed technical explanation
How to think about this question
VPC Gateway Endpoints use prefix lists and route table entries to direct S3 traffic over the AWS backbone, while Interface Endpoints use AWS PrivateLink with Elastic Network Interfaces (ENIs) in the subnet. When private DNS is enabled on the Secrets Manager interface endpoint, the Route 53 private hosted zone automatically overrides the public DNS resolution for the service's regional endpoint, ensuring traffic stays within the VPC. This approach also avoids data transfer costs associated with NAT gateways and internet gateways for these specific service calls.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Design Secure Architectures — This question tests Design Secure Architectures — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Create an S3 gateway endpoint and a Secrets Manager interface endpoint with private DNS, then remove NAT dependency for those service calls. — Option C is correct because VPC Gateway Endpoints (for S3) and Interface Endpoints (for Secrets Manager) allow private subnet instances to access these services over the AWS network without traversing the internet or a NAT gateway. Enabling private DNS on the interface endpoint ensures that the default Secrets Manager DNS name resolves to the endpoint's private IP, eliminating the need for a NAT gateway for those calls and reducing costs.
What should I do if I get this SAA-C03 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Based on the exhibit, a workload in private subnets must reach only Amazon S3 and AWS Secrets Manager. The team wants to eliminate internet exposure for those calls and reduce NAT gateway charges. What change should be made?
hard
A.Move the instances into a public subnet and restrict inbound access with security groups.
B.Add a NAT instance and disable the managed NAT gateway to lower cost.
✓ C.Create an S3 gateway endpoint and a Secrets Manager interface endpoint with private DNS, then remove NAT dependency for those service calls.
D.Use VPC peering to a shared services VPC and route all AWS service traffic through that VPC.
Why C: Option C is correct because VPC Gateway Endpoints for S3 and VPC Interface Endpoints for Secrets Manager allow private subnet instances to access these services over the AWS network without traversing the internet or a NAT gateway. Enabling private DNS on the interface endpoint ensures that standard DNS names resolve to private IPs, eliminating the need for NAT and reducing costs.
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Question Discussion
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