Google requires reinterviewing for fulltime while A9 does not. Also I am doing an internship at Facebook. Is it much harder to apply for new grad at google versus intern conversion interview?
Intern conversion takes into account feedback from your intern hosts about your work. It's not guaranteed that you will get a fflltime offer, but I think the odds are pretty high. I wouldn't make a choice based on this tbh, pick based on where you would actually like to intern.