Their articles aren't that deep and they mostly focus on similar topics.

I think it's perfectly possible for someone to have a backlog of work/experience that they are just now writing about.

If it were AI spam, I would expect many disparate topics at a depth slightly more than a typical blog post but clearly not expert. The user page shows the latter, but not the former.

However, the Rubik's cube article does seem abnormal. The phrasing and superficiality makes it seem computer-generated, a real Rubik's afficionado would have spent some time on how they cube.

Of course I say this as someone much more into mathematics than "normal" software engineering. So maybe their writing on those topics is abnormal.