One significant problem with the API Gateway / Lambda integration is that the protocol they use to communicate is JSON. JSON is a text-only encoding, i.e. anyth

One significant problem with the API Gateway / Lambda integration is that the protocol they use to communicate is JSON. JSON is a text-only encoding, i.e. anything that isn't valid UTF8 isn't valid JSON, and so if you need to pass something binary to/from the Lambda (e.g. an image), you need to base64 encode it, which I'm actually not even sure is at all possible with the API/GW templates. There are other issues, but this alone is a huge headache if you ever have to work around it.