I've worked on several large recurring payments platforms. It isn't rocket science, but let me tell you it is generally a pain in the ass to to manage recurring

I've worked on several large recurring payments platforms. It isn't rocket science, but let me tell you it is generally a pain in the ass to to manage recurring payments - in most of the systems I've worked in its easiest to just cancel and start a new one. The schemas are generally awful and make a lot of assumptions in the worst of ways. I wouldn't be shocked if the IA just finds it easier to manage manually than put in the large amounts of money for a refactor. One org I was with it took a Staff engineer nearly two years to rework the very odd weekly recurring feature to make it something that would be later made into something you could edit (of note, it was entirely separate in logic than the monthly recurring...)