I tried to search for remote jobs with the tag "python" so the url from it is: http://careers.stackoverflow.com/jobs?searchTerm=python&allowsremote=True
That returns 14 matching jobs, but this one for example is not in that search: https://careers.stackoverflow.com/jobs/84538/senior-software-developer-rackspace-the-sharp1-managed
Tried the same with "ruby" and remote: http://careers.stackoverflow.com/jobs?searchTerm=ruby&allowsremote=true resulting in 20 jobs but again, not listing this: https://careers.stackoverflow.com/jobs/102186/software-engineer-delivery-digitalocean
I found it was supposed to be a fixed bug: Careers Search Bug but apparently they are hiding information or the bug is still there and it's a concerning bug.
[edit] Adding screen capture of "python" search result:
[edit 2] Using a vpn to browse the site like I am inside the US I get 70 results from the first link. So yeah, results are filtered regionally, sadly.