Fix: AWS Lambda Timeout
Inspect CloudWatch duration metrics (p50 vs p99)
Lambda timeouts are almost always downstream latency (DB, HTTP) or cold-start + large init. Raise the timeout only after you confirm where the time is being spent.
Frequently Asked Questions
What causes AWS Lambda Timeout?
Lambda timeouts are almost always downstream latency (DB, HTTP) or cold-start + large init. Raise the timeout only after you confirm where the time is being spent.
How to fix AWS Lambda Timeout?
Check X-Ray traces or CloudWatch logs for the slow segment. Verify VPC-attached Lambdas have NAT/endpoints configured — cold starts on VPC can push past the default timeout.
Example fix from Kintify Fix
Input: AWS Lambda timing out after 3 seconds calling DynamoDB
Output: Check X-Ray traces or CloudWatch logs for the slow segment. Verify VPC-attached Lambdas have NAT/endpoints configured — cold starts on VPC can push past the default timeout.
Used by developers debugging real production systems