The page doesn’t list the year the startups were founded. I wonder if you’d see a good correlation to the founding year.

More startups on the list use Ruby than any other language, and it accounts for over fifty percent of the valuation. It was very popular with startups ten, twelve years ago, but may since have slipped?

On the other hand among younger companions es one might expect to see more Go, Node and maybe Rust?

Still, an interesting analysis.