Rafael Zamaris's wroclove.rb 2023 talk sharing stories and lessons from Upside's first year as lead maintainer of the Spree open-source e-commerce framework. Sets the context that Spree users need to scale from MVP to IPO and explores three major challenges every adopted open-source project faces — (1) roadmap/vision (GitHub discussions and projects used to publish a roadmap increased contributor engagement); (2) upgrades (avoid unnecessary breaking changes, favor depreciation schedules with log warnings, extract legacy APIs to separate gems like the old Spree API still used by Klaviyo); (3) maintainability of customizations. For customizations, walks through a cart-item-add example showing how users historically monkey-patched private methods (treating private interfaces as binding), the consequent upgrade pain, and Spree's shift ~5 years ago to encapsulated service objects with a built-in dependency-injection system where users register their own implementations. Covers decoupling UI rendering so admin-panel customizations happen through a helper API instead of Deface HTML injection. Closes on optional typing — comparing Sorbet and RBS, promoting the TypeScript-style attitude of shipping types to support library consumers without forcing them. Q&A covers how feedback on monkey-patching is collected, why events aren't yet introduced in Spree, and splitting 'add item' into separate 'add new' vs 'increase existing' strategies configurable via DI.