SAA-C03 Design Cost-Optimized Architectures Practice Question
A company has several VPCs in a single region that need to access an S3 bucket for data processing. Currently, traffic goes through a NAT Gateway in each VPC. What is the most cost-effective way to provide access to S3?
⚠ Common exam trap
Candidates often suggest Interface VPC Endpoints or keep NAT Gateways, forgetting that Gateway VPC Endpoints for S3 are completely free and avoid hourly charges and data processing fees.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Set up a Gateway VPC Endpoint for S3 in each VPC.
Gateway VPC Endpoints for S3 are free of charge and provide a direct, private connection to S3 within the AWS network. By replacing NAT Gateways—which charge per-hour and per-GB of data processed—with Gateway Endpoints, the company eliminates data transfer costs and the hourly gateway fee for S3-bound traffic.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Create an Interface VPC Endpoint for S3 in each VPC.
Why it's wrong here
Interface VPC Endpoints (AWS PrivateLink) for S3 carry an hourly charge and a per-GB processing fee. While they offer connectivity, they are less cost-effective than Gateway Endpoints for S3, which are provided at no additional cost. Interface endpoints should only be used if access from on-premises or different regions is required.
- ✓
Set up a Gateway VPC Endpoint for S3 in each VPC.
Why this is correct
Gateway Endpoints are a cost-free feature of VPCs that route traffic to S3 through the AWS private network. They do not incur hourly charges or data processing fees, unlike NAT Gateways. This makes them the most economical solution for any VPC-based workload that needs to communicate heavily with S3.
- ✗
Deploy a single NAT Instance in a shared services VPC.
Why it's wrong here
While a NAT Instance might be cheaper than a NAT Gateway in terms of hourly rates, it requires manual management, patching, and scaling. Furthermore, it still incurs data transfer charges across VPCs and regions. It is not as cost-effective or reliable as using a free Gateway VPC Endpoint for S3.
- ✗
Use a Transit Gateway to route all S3 traffic through a central VPC.
Why it's wrong here
Transit Gateway simplifies networking but introduces its own set of costs, including an hourly charge per attachment and data processing fees. Routing S3 traffic through a Transit Gateway just to reach S3 would be significantly more expensive than using localized Gateway Endpoints, which provide direct and free routing.
Visual reference
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
About these practice questions
Courseiva writes every SAA-C03 question from scratch — 149 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Amazon Web Services exam blueprint
This SAA-C03 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SAA-C03 exam.