Migrating a Production Rails App from Webpacker + Sprockets to Webpack + Jsbunding-rails : A…

The full story of modernizing a decade-old SaaS asset pipeline — without breaking production. I work in a SaaS company with a strong foothold in the aviation industry. When Rails 7 officially deprecated Webpacker and Rails 8 doubled down on Propshaft as the default asset pipeline, the writing was on the wall. For our platform — a large, multi-tenant SaaS application with over a decade of history — “we’ll get to it eventually” finally became “it’s now or never.” This is the story of a eight-month migration that touched 318 files, spanning 4,303 additions and 7,899 deletions across 234 commits. It was messy, instructive, and ultimately worth it. Here’s everything I learned. What We Were Working With. This wasn’t a typical rails new app. Built over ten years, it had accumulated a considerable frontend footprint: Webpacker 5 (Webpack 4 under the hood) managing React components, TypeScript...