This is confusing because you’re implying that Stripe Billing is used internally but another employee clarifies and says it’s not, it’s simply another billing service was created that predates Stripe Billing.
It used to be that Stripe could be relied on not to do this sort of corporate doubletalk. The OP asked a direct question and you've given a misleading PR answer.
I'm sure you're a nice person just trying to do your job, but your inevitable PR posts to HN, within minutes of anything Stripe-related coming up, are hurting your cause. The Stripe of the past would never have spewed propaganda like "This is the point of Stripe. A single stack that flexes with your business as it grows and pricing that's public" into HN threads. It's embarrassing, and what it's telling us is that culturally you've lost your way.
Maybe that's inevitable on your way to world domination, but if you guys can no longer communicate honestly or treat readers as intelligent, you'd be better off not posting here. I like Stripe, by the way. I know this is harsh but I would like it to be helpful.
It's of course your choice, jfyi