SAA-C03 Design Cost-Optimized Architectures Practice Question
A media company runs a 24/7 ingestion API on EC2 behind an Application Load Balancer and a nightly transcoding job that can resume from checkpoints. The API fleet runs at roughly 65 percent CPU all day, while the batch workers sit idle most of the time. The company wants to cut compute cost without risking the API. Which two changes should they make? Select two.
⚠ Common exam trap
It's easy for candidates to confuse Savings Plans with Reserved Instances, or assume Dedicated Hosts are a cost-saving measure, when in fact they are a premium isolation feature; the key is recognizing that Spot Instances are ideal for fault-tolerant, checkpointable batch workloads, while a Compute Savings Plan covers the predictable baseline without locking into a specific instance type.
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
✓
Purchase a Compute Savings Plan for the always-on API fleet.
A is correct because a Compute Savings Plan offers the largest discount (up to 66%) in exchange for a 1- or 3-year commitment to a consistent amount of compute usage (measured in $/hour), which perfectly matches the always-on API fleet that runs at a steady 65% CPU utilization. This plan applies to any EC2 instance family, region, or compute service (including Fargate and Lambda), giving flexibility while reducing costs for the predictable baseline load.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Purchase a Compute Savings Plan for the always-on API fleet.
Why this is correct
Correct. Compute Savings Plans discount steady usage across EC2 and other compute services without forcing a specific instance family. The API has predictable 24/7 demand, so a commitment fits the usage pattern and lowers cost safely.
- ✓
Move the transcoding workers to EC2 Spot Instances and checkpoint progress.
Why this is correct
Correct. Spot Instances are the best fit for interruptible, restartable batch work. Checkpointing limits the impact of interruption, so the company can absorb Spot interruptions while paying substantially less than On-Demand capacity.
- ✗
Replace the API fleet with Dedicated Hosts to lock in lower rates.
Why it's wrong here
Incorrect. Dedicated Hosts are primarily for licensing or isolation requirements, not cost reduction. They are usually more expensive and do not solve the cost problem for a steady web API.
- ✗
Buy Standard Reserved Instances for the batch workers and keep them running 24/7.
Why it's wrong here
Incorrect. Reserved Instances assume predictable long-running usage, but the batch workers are mostly idle. Paying for always-on capacity defeats the purpose of cost optimization for this workload.
- ✗
Increase the worker Auto Scaling minimum to prevent Spot interruptions.
Why it's wrong here
Incorrect. Raising the minimum keeps more capacity running continuously and increases cost. It also does not eliminate Spot interruptions, so it undermines the savings goal.
Quick reference
Cloud Service Model Comparison
| Model | You Manage | Provider Manages | Examples |
|---|---|---|---|
| IaaS | OS, runtime, apps, data | Hardware, hypervisor, networking | EC2, Azure VMs, GCP Compute Engine |
| PaaS | Apps and data | OS, runtime, middleware, hardware | Elastic Beanstalk, Azure App Service |
| SaaS | Data and settings only | Everything else | Microsoft 365, Salesforce, Workday |
| FaaS / Serverless | Function code only | Infra, scaling, runtime | Lambda, Azure Functions, Cloud Run |
| CaaS | Containers and apps | Kubernetes, OS, hardware | EKS, AKS, GKE |
Go deeper
Related to this question
About these practice questions
One of 302 original SAA-C03 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.