A Packwerk Retrospective - Shopify

This post is a retrospective on Packwerk, detailing its origins as a dependency management tool, its later adoption and subsequent removal of 'privacy checks' which were misused as an API design tool, and its weaknesses and blind spots such as not seeing dynamic constants, relying on Zeitwerk autoload directories, and not seeing dependencies outside the app directory. It also describes an effort to isolate the 'Platform Essentials' package, which revealed a bug in Packwerk and highlighted the need for inversion of control to resolve violations, often making code harder to understand.