How to check logs? Or what's in the queue?

Visit https://ap-southeast-1.console.aws.amazon.com/lambda/home?region=ap-southeast-1#/applications/lambda2sqs?tab=overview

Messages that had some sort of validation failure or repeatedly failed will be in the Dead letter queue.

Architecture

lambda2sqs originally started life as a bridge for Aurora CALL mysql.lambda_async payloads to SNS to be subscribed to. It has evolved to co-ordinate our Microservice architecture via a Amazon Simple Queue Service (SQS).

This is codified in template.yaml in AWS CloudFormation.

And deployed as SAM application in order to orchestrate and co-ordinate the queues.