A serverless API built with AWS Lambda serves latency-sensitive requests. The team observes intermittent slow responses during traffic ramp-ups and expects some users to hit the API immediately after a period of inactivity. Which configuration best reduces cold-start latency during these ramp-ups?

Increase the Lambda function’s memory setting; cold starts will always be eliminated regardless of traffic patterns.

Increasing memory can improve CPU allocation and may reduce execution duration and sometimes initialization time. However, it does not guarantee that initialized environments are available after idle periods. Cold starts can still occur without provisioned concurrency.

Switch the Lambda runtime to a newer language version and remove any VPC configuration so the function never cold starts.

Changing the runtime or removing VPC configuration can reduce initialization overhead in some cases (for example, by reducing ENI setup time for VPC). However, these changes do not provide deterministic warm capacity. Cold starts can still happen depending on traffic patterns and scale-down behavior.

Set an API Gateway stage variable to "warm" the function at request time, which forces immediate initialization.

API Gateway stage variables do not create a pre-initialized warm pool of Lambda execution environments. Even if the application reads a stage variable, it still cannot deterministically avoid cold starts without a Lambda feature such as provisioned concurrency.

What does this SAA-C03 question test?

Static NAT maps one inside address to one outside address.

What is the correct answer to this question?

The correct answer is: Enable Lambda provisioned concurrency on a published alias used by the API, and set a minimum provisioned concurrency greater than zero. — Provisioned concurrency initializes and keeps a specified number of Lambda execution environments ready behind a given alias. If the API routes to that alias (for example, an alias named 'live'), then after periods of inactivity, ramp-up traffic can invoke already-initialized environments rather than waiting for cold start initialization. Memory/runtime tweaks or networking changes can help performance in some scenarios, but they don’t provide the same deterministic cold-start mitigation. Stage variables do not control Lambda execution-environment lifecycle. Higher memory can speed up code execution but does not guarantee pre-initialized environments after idle periods. Runtime upgrades and removing VPC can reduce initialization overhead in some cases but still do not eliminate cold starts deterministically under variable traffic. API Gateway stage variables can alter request behavior but cannot force Lambda to initialize before the first post-idle invocation. Provisioned concurrency is specifically designed to provide a warm execution pool.

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.