SAA-C03 Exam Dumps : AWS Certified Solutions Architect - Associate (SAA-C03)

EC2 instances in private subnets cannot access the internet unless there is a NAT gateway or a NAT instance configured.

“To enable instances in a private subnet to connect to the internet or other AWS services, you can use a NAT gateway or NAT instance.”

— NAT Gateways – Amazon VPC

In this use case:

EC2 instances are in private subnets

They need to call external APIs (internet access)

The most operationally efficient and secure method is to place a NAT Gateway in a public subnet and update the route table for private subnets to route internet-bound traffic through it.

Incorrect Options:

A: Private subnets don’t support public IPs.

C: VPC peering doesn’t help reach the public internet.

D: Interface endpoints are for private connectivity to AWS services, not external APIs.

A. Kinesis Data Streams:Supports high throughput, strict ordering, multiple consumers, and data retention for 365 days.

B. SNS + SQS FIFO:Can enforce ordering but lacks native support for 500 KB messages and retention requirements.

C. EventBridge:Lacks strict ordering and message size compatibility.

D. SNS + Firehose:Not designed for strict ordering or large message sizes.

This question centers on improving scalability and global access performance.

Auto Scaling groups enable EC2 instances to scale dynamically in response to demand, ensuring availability during peak hours without manual intervention. Amazon RDS read replicas offload read traffic, improving read throughput and reducing latency on the primary database instance. Deploying Amazon CloudFront with S3 as origin accelerates delivery of static transaction documents globally by caching content at edge locations, reducing latency for users worldwide.

Option B focuses on vertical scaling (larger instances) and caching with ElastiCache, but it does not address global content delivery optimally. AWS Global Accelerator accelerates network traffic but is better suited for accelerating TCP and UDP traffic; CloudFront is generally preferred for HTTP content delivery.

Option C migrates workloads to Lambda and Aurora global databases, which is an advanced and potentially costly redesign that may not be necessary. Option D suggests moving to ECS and multi-AZ RDS but does not address global content delivery efficiently.

Therefore, option A uses proven scalability and caching best practices aligned with AWS Well-Architected Framework pillars for performance and operational excellence.