Hi all, is this customization doable in SC (not advanced)? https://developers.suitecommerce.com/add-a-button-to-remove-all-items-in-the-cart.html I'm more interested in knowing specially if this part can be done:

You shouldn't because these are core modules. You should do the other suggestion, which is to use the emptycart.nl endpoint

so on SC you can't extend core modules?

You shouldn't

but can I?

Until now you still can extend some core modules but if you check the comments, eventually they will be removed from a white list (allowed core modules), I think once they are migrated to other structure, typescript, etc. You will take the risk to expect your code will break in each upgrade (every 6 months)

and if i needed to add something to the backend, what would be the best way of doing it? is the extensibility api available on the backend?

The extensibility does not provide any way to extend/add logic to the backend side. So far you would need to re write completely the module you want to update. No fun at all.

so they are forcing you to either modify the code and pray to the netsuite gods that it doesnt break on an upgrade or to rewrite a module completely

You make it sound unreasonable