java still number one https://www.pluralsight.com/tech-index

I’m not sure how JS could come down to #4 from #1 in just one month?

Don't think it's the reason, but since I'm also not sure how they score, clojurescript started cashing external libraries.

How they score – the link is right there in the first paragraph. But it doesn’t answer why JS dropped so much during the first month.

this is not an absolute figure it’s a mashup of some metrics that you can interpret in one way or another at pluralsight, they choose to interpret it that java is on top