Google is your friend...

I don't have any resources to share but in my country the bank looks at my income - expenses then checks if I've defaulted on any debts. My limited understanding of the US system is that everyone has (often several) credit cards to build the necessary credit score. Here owning a credit card is for people drowning in debt who struggle to pay bills on time or in rare cases new money flexing their amex black, which is also shunned upon.

I've always thought the US system was super weird and backwards forcing debt on people. We don't have credit cards from every big chain and don't get harassed into signing up for cards in the mall, it's just not a thing.

We have the same safeguards you have, but we prove it with sensible spending instead of getting debt just to prove that we can pay it in time.

"looks at my income - expenses then checks if I've defaulted on any debts" - This is basically what we do in the US as well. But HOW do they do this in your country?

In the US, the loan originators look at year-end tax forms or recent pay stubs to verify income. They look at credit reports from e.g. Experian to verify defaults and other debt information.

The paychecks are verified at the bank, probably tax as well. For the debts we have a government authority which is usually the last resort for creditors. This authority also takes care of getting your cash, selling belongings etc to pay off creditors.

This is all open data and can be verified with just a phone call to the tax office and debt authority. Some private aggregators exist for convenience but they're regulated in what they're allowed to share and for how long.

The private companies are also required to notify me anytime someone checks my score, the government agencies aren't.

Australian here. When I apply for rentals I just went to my online banking and took a screenshots of the deposits.

It's been years since I had my mortgage approved but I vaguely recall the process being very similar.