Thanks to everyone who listened to my talk. I'll be turning the content in to a blog post (or two), but in the meantime the content is linked below. If you'd like to talk about Entity Centric Indexes or other things Elasticsearch you can find me on twitter.
Elasticsearch Transforms Demo Application
Demo Application I built to manage the transforms and generate demonstration data for the Scenarios I referenced.
Disclaimer: The code is 3-5 years old, and I honestly haven't touched it in 3 years. Hopefully it'll give an idea of how it can be achieved