I think you're proving exactly my point. SQL is intrinsically very close to the metal of your business logic, especially when it comes to general business logi

I think you're proving exactly my point. SQL is intrinsically very close to the metal of your business logic, especially when it comes to general business logic. General business logic is typically most critical and risky around the surface of payments. A JavaScript bug on your site around your shop preventing checkouts is very bad because you are indeed losing cash by the minutes. A poor domain model that doesn't properly associate active promotions to cart order lines could result in an incorrect charge amount and an irate customer.