This article fills a gap in my vocabulary for someone who shares some traits associated with ASD but doesn't suffer from any negative effects, i.e. is not in the scope of the medical autistic spectrum. The word is systemizing or being systematic. Autistic spectrum disorders then manifest in systemizing behaviour, but that doesn't mean only people with autism are systematic.
Another phrase you could add to your vocabulary to describe that is "broad autism phenotype" (BAP). People with BAP have significantly more autistic traits than the average person does, but not to the extent that a diagnosis of ASD is warranted.
BAP is very common in two groups of people (i) close blood relatives of people with ASD (parents, unaffected siblings, etc); (ii) people in STEM professions. (Of course, those two groups are overlapping–ASD is more common in children of STEM professionals than in the general population)
The term "systematising" is specifically associated with Simon Baron-Cohen's theories of the nature and causes of ASD, which are controversial. By contrast, the term "BAP" is much more neutral, it doesn't presume any particular theory about what ASD is or where it comes from.