They mostly use public repositories though.

Yeah, but that should also be a red flag.

Yeah at least when you interview locally in your areas, you get to meet them before you get a random test assignment.

But also online, once or twice I received these Leetcode style sites to register and do a few tests before we meet, which was weird for me and I just ignored it.

One of them later asked "Why I didn't have time to do it yet" and I told them I first meet people and check the fit before I do tests, like who the hell does that differently?

Hope it hasn't become a way more common thing.