--- title: "Code is the easy part, or how we refactored half the business to fix a janky script" url: https://daily.dev/posts/code-is-the-easy-part-or-how-we-refactored-half-the-business-to-fix-a-janky-script-ehd9lakxw source_url: https://swizec.com/blog/code-is-the-easy-part-or-how-we-refactored-half-the-business-to-fix-a-janky-script type: article source: "swizec.com" published: 2026-06-17T21:24:02.979Z updated: 2026-06-17T21:25:09.746Z tags: ["architecture"] reading_time: 14 upvotes: 0 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Code is the easy part, or how we refactored half the business to fix a janky script **[swizec.com](https://daily.dev/sources/swizec)** · 14 min read · 0 upvotes · 0 comments ## Summary A startup engineering war story about refactoring a broken billing system at Plasmidsaurus as the company scaled from $20M to near $100M ARR. The core insight: the real problem wasn't the janky Python invoicing script but a misaligned data model. The fix required introducing 'billing entities' as a new abstraction, migrating from QuickBooks to Rillet, building self-service tools for users and finance, and rewriting the invoicing script with proper tests. The process took 6 months, involved 6+ people, required extensive user interviews and watching people work, and was shipped incrementally to avoid breaking a live system processing thousands of orders daily. Result: month-end invoicing dropped from a week-long ordeal to 2 days. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Stripe Just Wants a Number](https://daily.dev/posts/stripe-just-wants-a-number-ujpbmth9e) · Lobsters · 1 upvotes · 0 comments --- Tags: [#architecture](https://daily.dev/tags/architecture) [View this post on daily.dev](https://daily.dev/posts/code-is-the-easy-part-or-how-we-refactored-half-the-business-to-fix-a-janky-script-ehd9lakxw)