In many regions / castes, the last name is specific to a caste. Also sometimes you can tell by appearance, e.g. I can often recognize Brahmins from my ancestral

In many regions / castes, the last name is specific to a caste. Also sometimes you can tell by appearance, e.g. I can often recognize Brahmins from my ancestral region just by looking at them. That said, one of the reasons I'm really skeptical claims that casteism is widespread in Silicon valley is that I have a last name that's caste-ambiguous (could be anything from dalit to brahmin) and yet I've never been asked my caste. So it's rather bizarre that casteism could be so widespread without me having ever encountered it.