Our custom solution to persistedquery cache clearence

I had a specific requirement wherein when author is editing headless content, by publishing content fragment, the latest content must realtime, immediately show at clientside. Out of box cache mechanism only provided TTL based. 

So I combined few ways, cooking custom solution to clear graphql query cache. 

Explain my custom solution here. 

https://medium.com/@bsaravanaprakash/how-to-eagerpurge-persistedquery-cache-upon-cf-publish-8864e0419c5e