I expect it's a combination of scripting, some manual effort, and AI. For what it's worth, I've seen lots of examples of this, and "usable optimizations" is en

I expect it's a combination of scripting, some manual effort, and AI. For what it's worth, I've seen lots of examples of this, and "usable optimizations" is entirely false. The PRs are often not working code. It's scattershot. The point isn't to make a PR that benefits the project in any way, it's to fill in the green square on the profile so it looks like there's a human doing things. Anyone giving this stuff more than a cursory glance would see that it's all bullshit. But the point isn't to stand up to scrutiny. It's to defeat abuse protection measures with legitimate-looking activity. And in the case of stars, to make it look to anyone who's just glancing at the star-ers that there are real people starring the repos. It's deviously clever and absolutely terrible.