These general concepts aren't going away anytime soon, but writing a new book specific to a PHP product (in 2019) would be outside of my comfort zone.

What is your audience?

Thanks for your reply!

I am thinking mid-level developers who are moving towards senior positions and/or developers who work in large organizations.

I've picked up a specific product (Laravel) to narrow my focus and ensure the sample codes are similar. Although the same concepts can be described in a framework-agonistic way.

There is also one behavior pull that I am expecting...there is a debate in the community that Laravel is not "enterprise-ready" and there has been efforts made to debunk that. I expect to get some network traction if I can convince those advocates to spread about this.🤞

DuckDuckGo on acid. Become the vessel and the universe will spell out the search queries for you, leading you to resources that could be helpful to you on your path. Call it intuition... I've stumbled upon many nuggets this way.