That doesn't mean it's without downsides or that they'd make the same choice today, with the options we have available now.

For example, they probably spend an absolute fortune on cloud costs, especially CI. Node, Go, Kotlin, Elixir or maybe even async+jit'd Python might all be 2-10x cheaper to run.

But I bet there are other choices that would have been worse. I often enjoyed working with Ruby at Stripe, especially once Sorbet came along.