Huge Map

What up Community!

I want to create a huge map.
The issue: I don't know how to optimize it.
I know something like 'VIS' exists but I also have read, that it is not viable atm.
Some people even recommend I should only use the scene system for creating the map.
Do you have any advice for me I should follow when creating a huge map?

Thank you in advance!

I mean just look up hammer map optimizations, most of them still work.

https://www.youtube.com/results?search_query=source+2+hammer+optimization