From your experience, who should specify the billing system? The Product team?
We're building Lago so that the right questions / decisions frameworks are asked during the implementation, so it's like a forcing power embedded in the product.
Our experience is, unless the Product/Biz team has been exposed to billing, they will never specify in a way that is precise enough, so the engineers who implement billing will have to think/assess/decide themselves.
Have someone from accounting/legal work at least 50% in bizdev; don't let them talk to engineering until they have sorted out what they want and, much more important, whether it is legal..
But equally important is to cut back engineering's enthusiasm for abstraction/unification": In my experience it is better to have 2 distinct, tested implementations against one pretty generic data model than trying to coerce both into one. Intellectually one can, but "oh so great billing concept" #3 or #4 will break ones neck.
I don't really think anything about billing is hard, it is just incredibly dull if done the pragmatic way.
We're building Lago so that the right questions / decisions frameworks are asked during the implementation, so it's like a forcing power embedded in the product.
Our experience is, unless the Product/Biz team has been exposed to billing, they will never specify in a way that is precise enough, so the engineers who implement billing will have to think/assess/decide themselves.