How they describe it: https://www.bundesbank.de/en/service/reporting-systems/exter...

Any single transaction exceeding 12500€ entering (or leaving) Germany has to be manually reported here. So for example if you're living in Germany and working remotely as a contractor for a US based company you'll probably have to report your income every month.

There are many exceptions that don't need manual reporting though, like if you're buying physical goods from overseas. I guess those are already automatically tracked through other ways.

For fun, I just tried to login at ~9:30 PM local time on a Sunday, and it said:

"Access Denied"

"You cannot access the resource you have requested at this time."

"The resource you have requested is protected by a policy restricting access to specific time periods. Your request has occured outside of those permitted time periods."