Long-running Lambda has no DLQ and no reserved concurrency

What it checks

Long-running Lambda has no DLQ and no reserved concurrency

Where it applies

Terraform: aws_lambda_function

CloudFormation: AWS::Lambda::Function

How to fix it

1. If this should stay Lambda: add reserved_concurrent_executions (start with 100) and dead_letter_config pointing at an SQS queue with a CloudWatch alarm on ApproximateNumberOfMessagesVisible.
2. If this is a batch / multi-step workflow: migrate to Step Functions Standard (durable, integrates with SQS/SNS) or ECS Fargate scheduled task (predictable cost, no 15-min ceiling).

Frameworks

• AWS Well-Architected REL.4
• AWS Well-Architected REL.5

These mappings are advisory, not an attestation of compliance.

Vendor documentation

All rules