These are pieces of knowlodge I got from several people and from my own experience.
back to the begining
If you want to learn more about a technology (or concept, etc), try to learn from who created it.
This is nice because you can see more about why things are the way they are.
Try not only learn from people who teach about it but not actually undestand it deeply.
In every company I worked for there were over engineered projects because they were too worried about scalling the app later.
I’d recommend to do the simplest thing first (with good sense) and only scale when needed.