[CuriouslyC]

That post seems extremely suspect. I'm guessing that what they mean when they say "the most in demand skills" is the skills that when present on a resume, increase the odds of a user being contacted by recruiters, which isn't so much in demand as hard to find. By that metric COBOL would probably have been at the top of the list if hired had clients that used it.

[rapfaria]

The fact that there's entries for Ruby and Ruby on Rails also makes me think this, perhaps this data was just parsed.

[wainstead]

I thought that was strange myself.

At the bottom of the page we get:

Methodology

This report is based on proprietary data gathered and analyzed by Hired’s data science teams. For the purpose of this report, Hired examined software engineering candidate interview requests and salary data from January 2020 through December 2021 inclusive. The data included reflects over 366,000 interactions between companies and software engineering candidates during this time period.

In addition to our proprietary data, we collected survey responses from more than 2,000 software engineers on the Hired marketplace to inform our understanding of software engineers’ working preferences.

[lbrito]

Do you have any evidence at all to support this or is it just a guess?

[CuriouslyC]

The evidence is that their "most in demand" includes none of top programming languages/tools according to pretty much anyone else. Therefore it's clearly not "in demand" in the sense that there are more job openings for those techs than for others. The explanation I posited seems like the most likely alternate definition.