Ask HN: I am writing a book. What would you want to see in it?

ASK HN: I am writing a book on Serverless Architectures (https://www.manning.com/books/serverless-architectures-on-aws?a_aid=serverless-architectures-on-aws&a_bid=145280de). It's going well but I want it to be the best book of its kind.

I need your collective wisdom HN. What kind of topics should it cover? What do you want to see in this book? And, what would make you recommend it to a friend?