It’s puzzling, OP. The default guess is, they are prominent writers in topics you are interested in.
They are prominent writers. But the topics don’t quite click.
All three happen to be programmers; but Pegah has only posted one answer on programming (and a curt one at that). And there’s nothing in your profile, OP, to indicate that you’re interested in programming.
Pegah has posted in Countries of the World, a topic you follow; and Iran, which she posts a lot about, is a Country of the World.
Jessica posts on Computer Science, which is… tech, and you do Electricity, which is… also tech. Joshua posts, among many other things, on Java, which is… tech, and on Science, which is… related to tech.
The recommended writer thing is a bit opaque; there’s a fair bit of just plain “this person is popular” in there. But they do seem to be popular writers that at least tangentially relate to your interests.