And it’s illegal to try and screen on anything except ability to do the job. Be very careful if you find yourself thinking in terms of software engineering interviews being a general intelligence test — you are setting yourself up for a discrimination suit.

https://en.wikipedia.org/wiki/Griggs_v._Duke_Power_Co.

As you clearly demonstrate, intelligence has a genetic basis. However, it does not follow that there is variation among humans at the relevant genetic loci. The variation may have become fixed in an ancestral population of modern humans.

What I gave there is an absolutely standard assessment of the situation from the point of view of population genetics. Of course intelligence "is genetic" in some sense: that's why dogs and cucumbers are less intelligent than humans for most definitions of "intelligent". The question is about the phenotypic significance of current intraspecific genetic variation.