How do people hide link schemes from Google crawlers?

I want to know how people hide their link-building schemes from Google crawlers to avoid penalties.

Some people hide spam links by secretly using networks of sites they own, showing one thing to normal visitors and another to search engines, hiding links in code or footers, temporarily marking them “nofollow,” or spreading them across low-quality sites and redirects, so it’s hard to see where they come from. But google’s system and human reviewers now spot these tricks, like weird link text, sudden jumps in link numbers, or links from unrelated sites, so even if you delay getting caught, you risk dropping in search rankings or having your site removed altogether.

I have noticed some people use tricks like JavaScript links, nofollow tags, or cloaking to hide link schemes from Google. It might work for a bit, but Google catches on eventually. I think it’s risky if you are trying to build something long-term.