A company has a steady, predictable workload that must run continuously (24/7) in a single AWS Region. The team wants the lowest cost option available for this steady usage, but also expects they may choose different EC2 instance families in the future (without re-buying compute discounts). Which AWS purchase option best meets these goals?

On-Demand Instances only, because they automatically adjust to future needs

On-Demand Instances provide flexibility, but they do not offer discounted pricing through a commitment. For a predictable 24/7 workload, a commitment-based option (Savings Plans or Reserved Instances) is typically required to achieve the lowest cost.

Standard Reserved Instances tied to a single instance type and Availability Zone

Standard Reserved Instances can be discounted, but they are much less flexible for changing instance families. If you switch to different instance types/families over time, you may not be covered by the original RI (or you would need exchanges that may reduce the economic benefit).

EC2 Spot Instances, because they are always cheaper than savings programs

Spot Instances can be cheaper, but their price is variable and capacity can be reclaimed, causing interruptions. For a workload required to run continuously (24/7), Spot is generally not the best fit unless the architecture can tolerate termination and the business requirements allow interruption.

What does this SAA-C03 question test?

Read the scenario before looking for a memorised answer.

What is the correct answer to this question?

The correct answer is: Compute Savings Plans, committed for a 1- to 3-year term in the Region — Compute Savings Plans are designed for steady, predictable usage where you want lower cost through commitment while retaining flexibility. By committing to a consistent hourly spend in a Region, you receive discounted pricing for eligible EC2 usage even when you change instance families later. This matches the requirement to run continuously and to avoid re-purchasing discounts when the specific instance family selection changes. Why others are wrong: On-Demand does not provide commitment-based discounts, so it usually won’t meet the “lowest cost” goal for a predictable 24/7 workload. Standard Reserved Instances are more tightly bound (instance type/region and sometimes Availability Zone), which reduces the ability to switch instance families without losing discount coverage. Spot Instances may be cheaper but can be interrupted; they do not align with a requirement for continuous 24/7 operation.

What should I do if I get this SAA-C03 question wrong?

Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.