AWS Interview DropIntermediate TierConcept+25 XP on read
Reserved Instances, Savings Plans, Spot, and On-Demand: how do you decide what mix to run for a given EC2 workload?
Core Summary
The decision runs on one axis: how predictable is the usage, not how important the workload is. Steady, known baseline load goes on Savings Plans, spiky or unknown load stays On-Demand, and anything interruption- tolerant goes on Spot. Reserved Instances are mostly the older, less flexible version of a Savings Plan today.
Hints
Hint 1: Predictability decides the purchase option, not criticality
Hint 2: Savings Plans are a spending commitment, RIs are a capacity commitment
Hint 3: Most real fleets are a blend of three or four of these at once