Writing Clean Elixir: Separating Pure and Impure Code with Ecto

Mixing business logic with database queries makes Elixir applications difficult to test, maintain, and scale. By mastering the separation of pure functions from impure side-effects, you can unlock the true power of functional programming. This written course guides you through restructuring Elixir codebases for maximum clarity and testability. You will learn to isolate your core domain rules from database interactions, resulting in faster test suites and more resilient system architectures. What you'll learn: - Understand the fundamental difference between pure functions and side-effects in functional programming - Apply Ecto's repository pattern to cleanly decouple database operations from core business logic - Design Elixir contexts that act as clean boundaries for your application features - Write fast, reliable unit tests for pure functions without complex database setup or mocking - Refactor tightly coupled Elixir code to extract domain logic from database layers You will begin with foundational definitions of purity and side-effects before moving into practical Elixir patterns and Ecto integrations. Through detailed written explanations and clear code examples, you will learn to transition an application from coupled to cleanly separated layers. This course is designed for beginner-to-intermediate Elixir developers who want to improve their application architecture, starting with core conceptual foundations. Start reading today to elevate your Elixir design skills and write cleaner, more maintainable code.