You have a video where you speak about DDOS and the max query depth.
I have the same problem as a user who set the following problem under Kickstarter:
graphql-java-kickstart/graphql-spring-boot#609
I took part in the discussion. I saw that Playground in your sample has also no connection to the graphql Backend but you execute the queries an get back the right exception. I use the actual version 11.0. Do you have some experience with the same problem which you can share withn us?