However universities and research seem to have something against common convenience and most of their offers are hard/impossible to find/search.
Do you have any resource where I can find PhD opening that offer VISA sponsorship?
https://www.google.com/search?q=phd+position+site%3Ahttps%3A...
Some PhD openings may not even be advertised, so politely asking (i.e. no generic spamming) existing students or faculty members is the only way to find out.
The difficult part is identifying professors that you'd like to work with.
My emails were clear, simple and respectful. I guess they have better things to do than to respond to random stranger on the internet.
I wish there was a kind of a job board for PhDs ..