A Lambda function processing financial transactions sees 3-5 second cold starts and misses a 200 ms response requirement for business-critical requests. Which feature minimizes cold starts?
Show answer and explanation
Answer: B
Provisioned Concurrency pre-initializes the requested number of execution environments, so library loading, deployment-code download, and connection setup are already complete when traffic arrives. Requests route to those warmed environments and start without the initialization phase, removing the cold-start penalty for the configured concurrency level.
Why the other options are wrong
- A. More memory allocates more CPU per invocation, which can shorten a warm invocation's runtime but does nothing to pre-initialize environments, so cold starts still occur.
- C. The timeout only extends how long a running invocation may execute before being killed; it has no effect on startup latency before execution begins.
- D. Entering a VPC generally adds initialization work for ENI attachment and networking setup rather than removing any; VPC placement governs network reachability, not cold-start time.
Exam tip. Provisioned Concurrency = pre-warmed execution environments that cut cold starts to near zero, at extra cost.