I was recently doing some work related to AWS Cognito, which I wasn’t previously familiar with, and it turns out to be pretty interesting. Stackery has a cloud-based app for building and deploying serverless applications, and we use Cognito for our own authentication. The thing I was trying to do was hard to figure out but easy once I figured it out, so I’ll include some code snippets related to my specific use case.

If you’ve dealt with Lambda functions you may have run across the RequestEntityTooLargeException - * byte payload is too large for the Event invocation type (limit 131072 bytes) AWS Lambda exception that occurs when a function is invoked with too large of a payload. Current AWS Lambda limits are set at 6 MB for synchronous/RequestResponse invocations, and 128 K for asynchronous/Event invocations.