ajankovic

I don't think you examined the code in full. main spawns 10 go routines that are constantly sending player scores to the game. That means 10 different players are sending their scores concurrently until someone reaches score of 100.

"Try not to become a man of success, but rather try to become a man of value." - Albert Einstein

Pretty much this. Get hold of your ego and be humble enough to take lessons from experienced people who have track record of delivering successful projects. It is imperative to get the basics right before being able to take on more responsibility later.

    "We don't rise to the level of our expectations, we fall to the level of our training."

Make sure you get as much training as possible before raising your expectations. It will be easier for you later when business expects senior output from you but you are under constant pressure on both personal and professional fields.

I was more thinking about language agnostic approaches for big enterprise projects.

Can anyone recommend a book that you would use as the guide for building a new software project from scratch? Like something that would provide good overall structural approach and best practices. The goal would be to end with as least amount of tech debt and codebase flexible enough to stand the test of time?

An interesting read but this kind of predictions don't work "in advance". Usually it's needed for some market player that is still unknown to show up first. That player will then serve as an example and solidify the argument. To know/feel what SaaS 2.0 is, in advance, would mean that you are the one driving it. SaaS 2.0 is not here yet.