✨This lightning talk was recorded at Code BEAM Europe 2023. If you're curious about our upcoming event check out: https://codebeameurope.com ✨ Fighting the Behemoth: turning a 2500-LOC module into some actually readable, testable Elixir code The talk will discuss steps and challenges that occurred while refactoring a towering non-trivial legacy Elixir module. Relevant steps include: designing a novel module architecture (based, based on the functional core - imperative shell pattern), refactoring code with special care for readability, creating a comprehensive and cohesive test suite to safely address migration from the legacy implementation.