- A
Buy EC2 On-Demand instances and rely on future Spot capacity for discounts
Why wrong: On-Demand pricing has no commitment-based discount, so a steady 24/7 workload generally remains costly. Relying on future Spot capacity does not match the predictable continuous demand and may also introduce interruptions unless the architecture is designed for them.
- B
Use Compute Savings Plans for the expected steady usage
Compute Savings Plans provide a discounted hourly rate in exchange for a commitment. They are the most flexible Savings Plans option and can apply across EC2 usage regardless of instance family or size changes, so the team can continue tuning instance types while still receiving discounted pricing for the committed usage.
- C
Buy Reserved Instances with a fixed instance type and region
Why wrong: Instance-specific Reserved Instances discount On-Demand but require matching the specified instance family/size and scope constraints. Frequent changes to instance families/sizes can reduce or prevent using the committed discount effectively.
- D
Buy Spot Instances and stop scaling to avoid interruption risk
Why wrong: Spot provides lower pricing but can be interrupted when capacity is reclaimed. Stopping scaling does not remove interruption risk; it only changes how capacity is adjusted. For a 24/7 service, this can still cause outages unless substantial fault-tolerance is built.
SAA-C03 Design Cost-Optimized Architectures Practice Question
This SAA-C03 practice question tests your understanding of design cost-optimized 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.
A web service runs continuously on AWS 24/7. The team expects steady compute usage for the next 12–24 months, but may change instance families/sizes as performance tuning continues. Which purchase option best reduces cost while keeping flexibility to change instance types?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"best"Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
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
Use Compute Savings Plans for the expected steady usage
Compute Savings Plans offer the lowest prices (up to 66% off On-Demand) in exchange for a commitment to a consistent amount of compute usage (measured in $/hour) for a 1- or 3-year term. Unlike Reserved Instances, they automatically apply to any EC2 instance family, size, OS, or region, giving you the flexibility to change instance types as performance tuning evolves, while still reducing costs for steady-state workloads.
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.
- ✗
Buy EC2 On-Demand instances and rely on future Spot capacity for discounts
Why it's wrong here
On-Demand pricing has no commitment-based discount, so a steady 24/7 workload generally remains costly. Relying on future Spot capacity does not match the predictable continuous demand and may also introduce interruptions unless the architecture is designed for them.
- ✓
Use Compute Savings Plans for the expected steady usage
Why this is correct
Compute Savings Plans provide a discounted hourly rate in exchange for a commitment. They are the most flexible Savings Plans option and can apply across EC2 usage regardless of instance family or size changes, so the team can continue tuning instance types while still receiving discounted pricing for the committed usage.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Buy Reserved Instances with a fixed instance type and region
Why it's wrong here
Instance-specific Reserved Instances discount On-Demand but require matching the specified instance family/size and scope constraints. Frequent changes to instance families/sizes can reduce or prevent using the committed discount effectively.
- ✗
Buy Spot Instances and stop scaling to avoid interruption risk
Why it's wrong here
Spot provides lower pricing but can be interrupted when capacity is reclaimed. Stopping scaling does not remove interruption risk; it only changes how capacity is adjusted. For a 24/7 service, this can still cause outages unless substantial fault-tolerance is built.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse Reserved Instances (which lock instance family) with Savings Plans (which offer flexibility across families), leading them to choose Option C because they think 'Reserved' is the only way to get a discount for steady usage.
Detailed technical explanation
How to think about this question
Compute Savings Plans are a flexible discount model that applies to any EC2 instance, including Fargate and Lambda, as long as the compute usage is within the committed $/hour amount. Under the hood, AWS calculates the discount based on the normalized compute unit (e.g., per vCPU and memory), so switching from a c5.large to an m6i.xlarge still receives the same percentage discount. This contrasts with Convertible RIs, which allow family changes but require a 1- or 3-year term and an exchange process that may incur a fee if the new instance has a higher cost.
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 Cost-Optimized Architectures — study guide chapter
Learn the concepts, then practise the questions
- →
Design Cost-Optimized Architectures practice questions
Targeted practice on this topic area only
- →
All SAA-C03 questions
1,040 questions across all exam domains
- →
SAA-C03 study guide
Full concept coverage aligned to exam objectives
- →
SAA-C03 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related SAA-C03 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Design Secure Architectures practice questions
Practise SAA-C03 questions linked to Design Secure Architectures.
Design Resilient Architectures practice questions
Practise SAA-C03 questions linked to Design Resilient Architectures.
Design High-Performing Architectures practice questions
Practise SAA-C03 questions linked to Design High-Performing Architectures.
Design Cost-Optimized Architectures practice questions
Practise SAA-C03 questions linked to Design Cost-Optimized Architectures.
SAA-C03 VPC practice questions
Practise SAA-C03 questions linked to SAA-C03 VPC.
SAA-C03 S3 lifecycle policy questions
Practise SAA-C03 questions linked to SAA-C03 S3 lifecycle policy questions.
SAA-C03 RDS Multi-AZ questions
Practise SAA-C03 questions linked to SAA-C03 RDS Multi-AZ questions.
SAA-C03 IAM policy practice questions
Practise SAA-C03 questions linked to SAA-C03 IAM policy.
SAA-C03 Route 53 failover questions
Practise SAA-C03 questions linked to SAA-C03 Route 53 failover questions.
SAA-C03 CloudFront practice questions
Practise SAA-C03 questions linked to SAA-C03 CloudFront.
SAA-C03 NAT gateway questions
Practise SAA-C03 questions linked to SAA-C03 NAT gateway questions.
SAA-C03 VPC endpoint questions
Practise SAA-C03 questions linked to SAA-C03 VPC endpoint questions.
Practice this exam
Start a free SAA-C03 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this SAA-C03 question test?
Design Cost-Optimized Architectures — This question tests Design Cost-Optimized Architectures — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use Compute Savings Plans for the expected steady usage — Compute Savings Plans offer the lowest prices (up to 66% off On-Demand) in exchange for a commitment to a consistent amount of compute usage (measured in $/hour) for a 1- or 3-year term. Unlike Reserved Instances, they automatically apply to any EC2 instance family, size, OS, or region, giving you the flexibility to change instance types as performance tuning evolves, while still reducing costs for steady-state workloads.
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.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
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 →
Last reviewed: Jun 11, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.