Short version, instead of letting APIGW do the routing and applying its own intelligence, it just passes the event straight to your lambda. Your lambda has to process it. The plugins I cited, will translate the Lambda event to a form that your standard API framework expects.
Those plugins also work if you put your lambda behind an application load balancer.
https://news.ycombinator.com/item?id=23668069
Short version, instead of letting APIGW do the routing and applying its own intelligence, it just passes the event straight to your lambda. Your lambda has to process it. The plugins I cited, will translate the Lambda event to a form that your standard API framework expects.
Those plugins also work if you put your lambda behind an application load balancer.