This is pretty neat. If you could take it a step further and have integrations to send the response payloads to other services like S3, SES, SQL insert into Redshift, etc then it would be great.
When this happens, ping me on twitter! I'll send some customers your way. One of my most frequently asked questions is if I know of an easy way to host webhook handler code. I usually point to Zapier, but I'd rather point to Hookdeck. :)
For python devs, this is a great framework to easily create and deploy them - https://github.com/aws/chalice.
These are AWS Lambda's hard limits, and are too low for many webhook applications.