What weight do phd interviews have?

Hi y’all. I have a few interviews coming up and was wondering how important they are? Are they more like undergrad alumni interviews or are they putting a lot of weight into these interviews?

Thanks!

Pretty sure they have a lot of weight (unlike for undergrad alumni interviews), but I guess this also depends on the program.

I know for my applications (finance, financial engineering), it does matter a lot. We also have more than one interview