I wonder how the backend works... Is it a microservice which queries over a globally distributed 'bank holidays' database, which has a frontend for some admin

I wonder how the backend works... Is it a microservice which queries over a globally distributed 'bank holidays' database, which has a frontend for some admin to add/remove bank holidays, and perhaps a custom approval workflow to approve/deny bank holidays, and maybe a system to make new bank holidays 'go live' on a certain date/time? Or is it just a static file someone wrote in vim and checked into git which got hosted as a static asset?