Billing systems are a nightmare for engineers • Hacker News Board

Re: Billing systems are a nightmare for engineers

#121

Post by msluyter » Wed, May 18, 2022, 6:58 PM UTC

I rewrote an invoicing system (originally in .NET) in Python and yeah, I totally feel this. All the system did was generate a CSV file that could be input into another system (Quickbooks, iirc). The original .NET version was nonsensical at times, replete with bugs, and I spent a lot of time trying to figure out what the original intent was (there were no docs, of course, and finance often had conflicting/incorrect ideas about what the system should do.) Version 1 had to simply replicate the csv generated by the original system exactly, which required purposefully writing some bugs that I discovered along the way.

But yeah, there were all sorts of nasty complexities -- this was a usage based system, but there were (optional) tiers (pay less for higher tiers), as well as certain time segments that were discounted. And then there were cases where multiple accounts could share a set of data and get a discounted rate and/or only one of the accounts would be billed. And on and on....

One lesson I drew from this experience was that, when discussing things with finance to try to figure out what the requirements were, it really helped to have pictures. I would create these elaborate usage/time graphs, and color in portions to reflect different billing/pricing scenarios. These made it much easier to discuss the current/future behavior of the system. Because saying "really, this is simply the integral of a usage function over time" didn't fly.

Re: Billing systems are a nightmare for engineers

#122

Post by burnished » Wed, May 18, 2022, 6:59 PM UTC

bckr wrote: post #105

AnhTho_FR wrote: post #82

Earlier quoted context omitted.

I'm Anh-Tho, one of Lago's co-founders here. Thanks for sharing! What did you do then? I'm curious!

Hey, Anh-Tho, just as a point of feedback, since you're leaving a lot of comments in this thread, it's not necessary to introduce yourself in each one. Most folks will be scanning the whole thread and seeing your introduction gets repetitive and breaks the conversational tone and makes it overly commercial. Thanks.

I fear if they did not they'd be accused of something else. I agree with your observation but I don't think there is an obvious solution as you imply.

Re: Billing systems are a nightmare for engineers

#123

Post by robot » Wed, May 18, 2022, 6:59 PM UTC

Problem is it still requires an API to integrate. Stripe has all these capabilities but API integrations are needed to use them. If you are looking to build a micro SaaS without needing to deal with billing API integrations check out our software: https://saasbox.net. Built for completely eliminating any billing related SW development. It doesn't handle all the corner cases mentioned in the article, but some of them are handled, such as plan upgrade / downgrades with pro-rating, editing plans on the fly, migrating users across plans, notifying your application on those changes.

Re: Billing systems are a nightmare for engineers

#124

Post by spookthesunset » Wed, May 18, 2022, 6:59 PM UTC

dboreham wrote: post #108

Note OP makes a billing product (OSS, granted) so is motivated to characterize the field as complex and hard. In reality billing is just like many other processes humans engage in. For sure it's more complex than computing prime numbers, but hey try writing software to capture medical services processes :) In the end this is exactly what engineers are supposed to do: figure out ways to model/capture/represent complex…

Or better, buy a billing system instead of inventing one inhouse. Billing is hard to do correctly. For one thing it interconnects with so many different platforms in your company. For another thing, the cost of fucking something up is high--people don't exactly like seeing mistakes in their bill. Hell, think about tax... you wanna deal with that shit?

To do it "correct" you've got to have people who truly understand accounting concepts like double entry bookkeeping, financial reporting, cash vs. accrual, financial regulations, auditors, etc. Unless your company's product is billing, good luck hiring an engineer who knows this shit.

But trust me from experience. Don't build your own billing system. There are several good ones out there that will grow with your organization. Buy one.

Re: Billing systems are a nightmare for engineers

#125

Post by ben7799 » Wed, May 18, 2022, 7:01 PM UTC

I agree with thesis but there are entire aspects of this that he didn't even touch upon. There is a multiverse of different billing nightmares for engineers.

I worked on a piece of software that bridged billing data from IBM mainframes out to the web. The hoops that had to be jumped through to get data out of the mainframes and the number of hacks and kludges involved was legendary. Likely everyone here has paid many bills in their life on websites that used that software. At one point I knew the vast majority of my personal bills had gone through it. Credit Cards, Utilities, Gas cards, etc.. Stuff everyone had to pay with paper before the web.

Re: Billing systems are a nightmare for engineers

#126

Post by colejohnson66 » Wed, May 18, 2022, 7:02 PM UTC

ben7799 wrote: post #125

I agree with thesis but there are entire aspects of this that he didn't even touch upon. There is a multiverse of different billing nightmares for engineers. I worked on a piece of software that bridged billing data from IBM mainframes out to the web. The hoops that had to be jumped through to get data out of the mainframes and the number of hacks and kludges involved was legendary. Likely everyone here has paid many…

Could you expand on what kind of hacks/kludges were required?

Re: Billing systems are a nightmare for engineers

#127

Post by piva00 » Wed, May 18, 2022, 7:04 PM UTC

spookthesunset wrote: post #124

dboreham wrote: post #108

Note OP makes a billing product (OSS, granted) so is motivated to characterize the field as complex and hard. In reality billing is just like many other processes humans engage in. For sure it's more complex than computing prime numbers, but hey try writing software to capture medical services processes :) In the end this is exactly what engineers are supposed to do: figure out ways to model/capture/represent complex…

Or better, buy a billing system instead of inventing one inhouse. Billing is hard to do correctly. For one thing it interconnects with so many different platforms in your company. For another thing, the cost of fucking something up is high--people don't exactly like seeing mistakes in their bill. Hell, think about tax... you wanna deal with that shit? To do it "correct" you've got to have people who truly understand…

Similar experience in some companies in my CV. Billing systems aren't fun to maintain, develop nor debug. They take a non-trivial amount of time when done wrong and if you are building one in-house you'll inevitably run into some mistake.

Buy a billing system, it'll save engineering hours having to deal with it and if you choose right they'll scale with your company.

Re: Billing systems are a nightmare for engineers

#128

Post by AnhTho_FR » Wed, May 18, 2022, 7:05 PM UTC

daxaxelrod wrote: post #75

AnhTho_FR wrote: post #52

Earlier quoted context omitted.

Hey @daxaxelrod! I'm one of the cofounders of Lago, the lib will be opened very soon, we're in the final steps of QA, that's why. I will make sure to ping you back here when it is. We wanted to share this post about our first-hand experience with billing a bit ahead of this. Thanks for your patience!

Hi! Cool, can't wait to poke around. I've used killbill https://github.com/killbill previously and would be interested in your offering.

Will ping you asap!

Re: Billing systems are a nightmare for engineers

#129

Post by spookthesunset » Wed, May 18, 2022, 7:05 PM UTC

Rafsark wrote: post #117

bcrosby95 wrote: post #58

I've had to deal with subscription based billing, and in my experience it wasn't a nightmare. There are some corner cases, but, those exist in every domain. And the stakes are definitely raised since you're dealing with people's money. Usage based billing sounds like a nightmare though. Taxes in the USA are a nightmare too. I have a friend that lives on a street, and for one side the tax rate is 7.5%, and the other s…

For simple subscription-based billing, it's somehow not this hard, you are right. It also depends on how much plans you provide to your customers, and you still need to scratch your head for upgrades and downgrades. I truly believe in usage-based billing, so I do think pricing are getting more and more complex over time. Taxes are a nightmare for everyone also (in Europe too...)

Dont forget price changes. Gotta deal with that. Then discounts, trials, weird durations, and a bunch of other shit I forget.

My advice for anybody thinking of building their own subscription management system is to stop and go look at something like Zuora. You do NOT want to get stuck maintaining some home grown subscription management system--it will never be better than Zuora and you'll always be playing catchup, leaving your company unable to quickly react to the market. All the time spent adding functionality you can buy from a third party is money that you could have invested in your actual product. And worse, the fact you couldn't quickly react to the market because some key feature was missing in your homebrew thing is literally leaving money on the table.

Re: Billing systems are a nightmare for engineers

#130

Post by asciimike » Wed, May 18, 2022, 7:05 PM UTC

Nit: there's a lot of noise being made in comments about it being an open source product, but I haven't found the source (maybe I have to speak to an expert to get it?). github.com/getlago has the docs, which is nice (and gives a lot more info than is available on the website about how the product works), but not quite the same.

Also note:

> Our open-core version is forever free. We will introduce paying add-ons in the future, with a consumption-based approach.