So at work, I suddenly got asked to help interview a ton of Indians, Mexicans, and various Bulgarians for hardcore devops guru positions. Since mid-April, we've done over 50 interviews (that's a lot).
A couple of interesting observations:

- On average, the ratio of top-tier specialists to the number of interviews doesn't depend on the country. It's pretty much the same everywhere: 1 solid person per 7-10 interviews. Even among Indians.
- Indians have noticeably more female candidates. Well, to be precise: we didn't get a single one from Bulgarians or Mexicans. But from Indians, 4 out of 20!
- Surprisingly, a lot of Mexicans really love to chat after the interview about random stuff like "oh, where are you from, what's your project, what time is it for you". If you don't stop them in time, it can go on for a while. Nobody else does this.
- The most technically strong candidate was from Bulgaria. Arguably, the strongest one I can remember from the past couple of years of interviews.
- One candidate suddenly launched into a speech at the end of the interview about how amazing he is (he's really not), how much he loves this kind of work (he almost teared up) and how he absolutely needs to be hired. I have no idea what he was expecting, but you just shouldn't do that.