A development team expects their EC2 utilization to average about 40% of capacity across the next year. They want to lower costs but need flexibility to change instance families and sizes as requirements evolve (for example, moving from compute-optimized to memory-optimized instances). Which AWS purchasing commitment best meets the goal of reducing cost while keeping flexibility?

All Upfront EC2 Instance Reserved Instances for a single instance family to maximize discount.

EC2 Instance Reserved Instances are scoped to specific instance attributes (including instance family and typically additional attributes like operating system/tenancy). If the team needs to switch instance families as requirements change, the discount may not apply to new families, reducing flexibility and potentially reducing savings.

Spot Instances for the entire workload so they can avoid commitments entirely.

Spot can reduce cost, but it is not a commitment that guarantees baseline capacity. The prompt specifically asks for a purchasing commitment that reduces cost while keeping flexibility around instance family and size. Spot also introduces interruption and capacity variability that are not part of the stated requirement.

On-Demand Instances with increased Auto Scaling to match the peak month only.

Using On-Demand with scaling to the peak month does not satisfy the objective of reducing cost via purchasing commitments. Scaling to peak capacity increases spend relative to a 40% average-utilization target and removes the primary cost lever (discounted commitment) described in the prompt.

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, sized to the expected average usage, because they provide savings across instance families and usage types. — Compute Savings Plans offer discounted pricing for a consistent hourly usage level while still allowing flexibility to change instance families and sizes within the covered scope. Compared with instance-scoped Reserved Instances, they better fit environments where architecture and instance selection will evolve. Basing the commitment on expected average utilization helps prevent overpaying relative to actual baseline usage. Instance Reserved Instances are more tightly scoped, which conflicts with the requirement to switch instance families. Spot may lower costs but is not a commitment-based approach and introduces capacity variability/interruptions. On-Demand scaling to peak prioritizes capacity and can increase cost, failing to leverage commitment-based discounts.

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.