A latency-sensitive API is implemented with AWS Lambda. During traffic ramp-ups, users sometimes experience slow responses due to cold starts. The team wants to ensure fast initialization for a baseline level of concurrent requests. Which AWS feature should they use?

Increase reserved instances for EC2

Reserved Instances apply to EC2 capacity. They do not warm or pre-initialize Lambda execution environments, so they do not directly prevent Lambda cold starts.

Enable S3 event notifications for every request to the API

S3 event notifications trigger when objects are created/updated in S3. They are not part of Lambda cold start mitigation for API invocations and would add unnecessary event-processing complexity without warming Lambda in a reliable way.

Decrease the function timeout to reduce execution variability

Changing the timeout affects how long Lambda can run before terminating, not whether the runtime environment is pre-initialized. It does not address cold start latency and may cause failures for requests that require more time.

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: Lambda provisioned concurrency — Use Lambda provisioned concurrency. It is designed specifically to provide predictable, low-latency Lambda performance by keeping a defined number of execution environments already initialized. By setting a baseline provisioned concurrency level (for example, on a function alias), the platform can serve invocations immediately during normal traffic and ramp-ups, greatly reducing cold-start-related slow responses. EC2 Reserved Instances do not affect Lambda runtime initialization. S3 event notifications are unrelated to the Lambda invocation path and do not provide reliable warming for API traffic. Decreasing the function timeout does not change cold start behavior and can increase error rates if requests legitimately require more time.

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.