What do you know about SAAS UI?

Hi,

I would like to know the different parts involved in a classic SAAS UI.
I mean the ADMIN page, the landing page...

For each one can you recommand templates to explore for non designers,
I also would like to hear about any tips regarding these templates, like how useful are they, how to customize it, is minimalism in the design a good choice, is the user really design sensitive...?

This is what I found useful so far:

https://reactsaastemplate.com/ : full SAAS React frontend
https://coreui.io/?affChecked=1 : CoreUI Admin template

Thank you.