SAA-C03 Design Cost-Optimized Architectures — Timed 10 Questions

Question 1

An internal rendering job runs on EC2 workers in an Auto Scaling group. Each job writes checkpoints every few minutes to S3 and can resume from the latest checkpoint after an interruption. The queue depth varies sharply, and the team wants the lowest possible compute cost. Which two changes should they make? Select two.

10 minute time limit — choose an answer to begin.

Accepted Answer

Run the worker fleet on EC2 Spot Instances.. Spot Instances can be interrupted with a two-minute warning, and since the rendering job writes checkpoints to S3 every few minutes and can resume from the latest checkpoint, it is fault-tolerant to interruptions. This allows the team to leverage the significantly lower cost of Spot Instances (up to 90% off On-Demand) while maintaining job completion, achieving the lowest compute cost for variable queue depths.

Answer

Purchase Dedicated Hosts so the fleet keeps physical servers reserved for the workload.

Answer

Run the entire fleet on On-Demand Instances to avoid any interruption risk.

Answer

Move the workers to AWS Outposts to keep compute close to the data.

Question 2

Match each data-retention scenario to the most cost-effective Amazon S3 storage class. Assume the retrieval pattern and access-latency requirement are the most important constraints.

Accepted Answer

S3 Standard: Data accessed frequently; need low latency. S3 Standard is for frequent access; Intelligent-Tiering optimizes cost for unknown patterns; Standard-IA for infrequent but rapid access; Glacier Flexible Retrieval for minutes; Glacier Deep Archive for hours.

Answer

S3 Glacier Flexible Retrieval: Data accessed infrequently but requires rapid access when needed; retrieval time milliseconds

Answer

S3 Glacier Deep Archive: Data that can be retrieved within 1-5 minutes

Question 3

Match each workload to the AWS pricing option that most directly minimizes cost while still meeting the stated flexibility requirements. Use each option once.

Accepted Answer

Spot Instances: A fault-tolerant data processing job that can be interrupted and resumed. Spot Instances are cheapest for fault-tolerant workloads; Reserved Instances offer discounts for steady usage; On-Demand is flexible for short tests; Savings Plans provide lower rates for committed use; Dedicated Hosts meet compliance for strict workloads.

Answer

Spot Instances: A production database server running 24/7 with predictable load

Answer

On-Demand: A fault-tolerant batch job that can handle interruptions

Question 4

Match each workload to the most cost-effective compute model or service choice. Focus on how often the workload runs, whether it is interruption-tolerant, and how much administration the team wants to avoid.

Accepted Answer

Short-lived automated tasks that run every minute: AWS Lambda. Lambda is ideal for short, frequent tasks; Batch on Fargate for nightly jobs; Spot Instances for fault-tolerant workloads; Reserved Instances or Savings Plans are more cost-effective for consistent steady-state loads like a stateful e-commerce platform; ECS Fargate reduces management.

Answer

Stateful e-commerce platform with consistent load: On-Demand EC2 instances

Question 5

A service in private subnets downloads product images from Amazon S3 and stores job state in DynamoDB. A NAT Gateway is currently the only route to AWS services, and the monthly bill is dominated by NAT data processing charges. Which two changes will most directly reduce that cost? Select two.

Accepted Answer

Create a gateway VPC endpoint for Amazon S3.. A is correct because a gateway VPC endpoint for Amazon S3 allows instances in private subnets to access S3 directly over the AWS network without traversing the internet or a NAT Gateway. This eliminates NAT data processing charges for S3 traffic, which is the dominant cost driver in this scenario.

Answer

Add an internet gateway and move the instances into public subnets.

Answer

Replace the NAT Gateway with a Site-to-Site VPN connection.

Answer

Create an interface endpoint for S3 instead of a gateway endpoint.

Question 6

Match each private-networking or content-delivery scenario to the AWS feature that most directly reduces cost while meeting the connectivity requirement.

Accepted Answer

CloudFront: Content delivery with low latency to global users. Each AWS feature directly reduces cost for the given scenario: CloudFront for latency, VPC Peering for intra-region, Direct Connect for hybrid, Transit Gateway for inter-region, Shield+CloudFront for security, and Global Accelerator for inter-region data transfer costs.

Answer

Transit Gateway: Point-to-point connectivity between two VPCs

Answer

Global Accelerator: Low-latency content delivery to edge locations

Question 7

A containerized service runs in private subnets and retrieves secrets from AWS Secrets Manager and configuration parameters from AWS Systems Manager Parameter Store on startup. A NAT Gateway is currently used only for these AWS API calls, and the security team wants to eliminate that recurring charge. Which two endpoints should be added? Select two.

Accepted Answer

Create an interface VPC endpoint for AWS Secrets Manager.. AWS Secrets Manager is accessed via API calls over HTTPS, and an interface VPC endpoint (powered by AWS PrivateLink) allows private connectivity to the service without traversing the internet or a NAT Gateway. This eliminates the need for the NAT Gateway for Secrets Manager traffic, reducing costs and improving security by keeping traffic within the AWS network.

Answer

Create a gateway VPC endpoint for Amazon S3 instead.

Answer

Add an Internet Gateway and send the traffic through public subnets.

Answer

Replace the NAT Gateway with a NAT instance.

Question 8

A line-of-business application runs on EC2 instances 24/7 with predictable usage for the next year. The application will stay in the same Region, and the team does not want to manage capacity interruptions. Which two purchase options can reduce cost compared with pure On-Demand pricing? Select two.

Accepted Answer

Buy Compute Savings Plans for the expected steady usage.. Compute Savings Plans (A) offer a flexible discount (up to 66%) in exchange for a 1- or 3-year commitment to a consistent amount of compute usage (measured in $/hour), automatically applying to any EC2 instance family, region, or even AWS Fargate/Lambda. This reduces cost compared to On-Demand while avoiding capacity interruptions, as the commitment covers the predictable steady-state usage. Standard Reserved Instances (B) provide a similar discount (up to 72%) for a specific instance family in a specific region, also with a 1- or 3-year term, and guarantee capacity for the specified AZ if you choose a zonal reservation, ensuring no interruptions.

Answer

Move the fleet to Spot Instances.

Answer

Use Dedicated Hosts to reserve physical servers for the application.

Answer

Stay entirely on On-Demand Instances because they are already the cheapest option.

Question 9

A compliance archive writes one log file per day to Amazon S3. The logs are almost never accessed after day 30, but if they are needed they must still be retrievable in milliseconds. They must be deleted automatically after one year. Which two lifecycle settings should you apply? Select two.

Accepted Answer

Transition the objects to S3 Glacier Instant Retrieval after 30 days.. S3 Glacier Instant Retrieval provides millisecond retrieval times for archived data, meeting the requirement that logs must be retrievable in milliseconds after 30 days. This storage class is designed for long-lived, rarely accessed data that still needs immediate access, making it ideal for compliance archives that are almost never accessed but must be available instantly when needed.

Answer

Transition the objects to S3 Standard-IA after 30 days.

Answer

Keep the logs in S3 Standard indefinitely and delete them manually when needed.

Answer

Replicate the logs to another Region for cheaper archival storage.

Question 10

An application stores user-uploaded binaries in S3. Access is unpredictable for the first month, then most objects become cold. The team wants the cheapest approach that avoids manually guessing access patterns. Which two actions are best? Select two.

Accepted Answer

Enable S3 Intelligent-Tiering on the bucket.. S3 Intelligent-Tiering automatically moves objects between access tiers (frequent, infrequent, archive instant, and deep archive) based on changing access patterns, without manual lifecycle rules. This is ideal for unpredictable access in the first month followed by cold storage, as it optimizes cost by charging only for the storage tier actually used per object, with a small monthly monitoring fee per object.

Answer

Keep all objects in S3 Standard because lifecycle transitions add too much management.

Answer

Copy all binaries to Amazon EFS so retrieval is faster.

Answer

Disable versioning because S3 Intelligent-Tiering needs it to work.