FFS, It's not illegal discrimination.

In the USA discrimination is 100% legal if 1) the group being discriminated against is not specifically defined as a protected group under law OR 2) it's a legitimate job requirement.

Requiring programmers to know how to program also discriminates against non-programmers but non-programmers aren't a protected group.

Requiring a stocker to be able to lift 30 pounds discriminates against the disabled. The disabled are a protected group, but it's a legitimate job requirement for a stocker to be able to move the stock around.

If you're hiring for a senior engineer it's not illegal discrimination because 1) it's a legitimate job requirement and 2) young people are not a protected group under law (only people over 40 are)

Out of my own personal curiosity. How does the protection for people over 40 work?

in which world? because every job posting I have ever seen requires years of doing x or y.