The whole point of TFA is that billing systems are way more complex than they appear to be. If you're trying to build a billing system, how do you "copy" what these big companies do, when most of the effort is neither obvious nor visible?
It's easy in theory: 'just do it', 'just copy', BUT the challenges are in - the tiny details (that can have a huge impact: we're talking 'billing' and 'money' here) - the maintenance: it's a living organism: you will inevitably change your pricing, your payment processor, the way you bill, your back-end/front-end etc
Technically the point of TFA is to market billing software. Billing systems are complex in that they can consist of many different moving parts, but billing system are also simple in that they are easily understood. Billing has to be easily understood, else you'll quickly scare your customers away. Complexity and simplicity are not necessarily at odds with each other. The meat of TFA is mostly about how billing systems can quickly become a time consuming endeavour which again isn't at odds with simplicity.
I disagree. Billing has to be correct - that’s billing rule #1. You can have an easily understood pricing plan, but implementing that plan correctly and consistently in a way that you can defend and audit can be very complicated.
Just take the simple example of implementing anniversary billing for a customer who signs up on the 30th of the month. What date do you bill them when the month has less than 30 days? What about when it has more than 30 days? What about when your customers are spread through 4 time zones? What about when daylight savings starts and ends? Do most engineers understand time and time zones well enough to get this right?
These questions are fundamental to correct billing at any kind of scale, and the answers are not simple, or at least I don’t think they are.
We established earlier that billing is likely to be complicated, but that doesn't mean it isn't simple. Simple things can be complex. Simple refers to ability to understand, while complexity refers to scale of interconnected parts. They are not at odds with each other.
> the answers are not simple, or at least I don’t think they are.
I think you can make a strong case that business isn't simple, but billing systems only need to serve the needs of business after business has already figured things out. You cannot bill at all, even without a formal system, if you haven't answered these questions. A billing system merely needs to adopt the answers that are already understood.
I’m sorry but I consider complexity and simplicity to be antonyms - and so does the thesaurus! https://www.thesaurus.com/browse/complex
> billing systems only need to serve the needs of business after business has already figured things out
Billing is a fundamental part of your product and your GTM. Getting it right gives you an advantage, especially in terms of trying different approaches. Getting it wrong can be a burden on the business, especially if you find out that you need to re-price.
As someone who also works in billing and subscription management, I 100% agree with everything you said and want to add an extra thing:
Even when the answers ARE simple, there's so many of them that you end up realising you want to pay someone else to make it their problem instead.