Well, in Node you can run an express server on a URL lambda which is independent of API gateway. It's slightly cheaper, faster deployments, and you get much better error messages. The tradeoff is you must implement your own security considerations. Works well for me because has capabilities for addressing some concerns and most API's I do in projects don't need 90% of what API gateway is.

I haven't found a similar option in Python. All the Lambda servers I see on Python are explicitly linked to API gateway.