SAA-C03 Design Cost-Optimized Architectures Practice Question
A company is running a large-scale batch processing job that can be interrupted and resumed without loss of data. The job runs for several hours every weekend. Which instance purchasing option will provide the highest cost savings?
⚠ Common exam trap
SAA-C03 often tests the misconception that Reserved Instances are always cheapest — candidates must recognize that for interruptible, fault-tolerant workloads, Spot Instances deliver far greater savings than any commitment-based option.
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
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Spot Instances
Spot Instances offer up to 90% discounts compared to On-Demand pricing by using AWS's spare EC2 capacity. Because the batch job is interruptible and can resume without data loss, it perfectly matches the Spot use case — workloads that tolerate the two-minute interruption notice when AWS reclaims capacity. This makes Spot the most cost-effective choice for fault-tolerant, flexible workloads.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
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On-Demand Instances
Why it's wrong here
On-Demand Instances are the most flexible but also the most expensive purchasing option. They are best suited for short-term, unpredictable workloads that cannot be interrupted. For a batch job that runs periodically and can handle interruptions, using On-Demand would result in significantly higher costs than other available AWS options.
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Spot Instances
Why this is correct
Spot Instances offer the deepest discounts in exchange for the possibility that AWS may reclaim the capacity with a two-minute notice. Since the application can resume progress after being stopped, the company can maximize savings by utilizing these instances during the weekend when spare capacity is often high.
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Reserved Instances
Why it's wrong here
Reserved Instances require a one-year or three-year commitment to a specific instance type and region. While they offer substantial discounts, they are designed for steady-state workloads that run 24/7. Paying for a reservation that is only utilized during weekends would result in a higher effective hourly rate than Spot.
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Dedicated Hosts
Why it's wrong here
Dedicated Hosts provide a physical server fully dedicated to a single customer, usually to meet strict licensing or regulatory requirements. They are the most expensive way to run EC2 instances. Using them for a batch processing job without a specific licensing requirement would be an inefficient and costly architectural decision.
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.