The 14 pains of building your own billing system - Arnon Shimoni

This is another one of those great posts that dives into a topic that seems relatively mundane like "We need to bill our customers." and highlights the myriad of edge cases that arise. This often is overlooked in build-buy decisions and can result in underestimating complexity of the solution required. Shimoni highlights 14 pain points: Idempotency, Date Handling, Proration and "Leftovers", Usage Metering, Invoice Formatting, Complex Customer Hierarchy, Payment Collection and Churn Prevention, Pausing & Resuming, Crediting & Refunding, Tax Handling, Custom Deals, Human Error, Selective Pricing Changes, and Revenue Recognition & Accrued Revenue.