One of the most common Drupal architecture questions is: should this workflow live in ECA or custom code? The answer depends on your project version, workflow complexity, and team capabilities. This guide provides a practical decision framework. Current State of Each Option Rules Widely used in Drupal 7 with mature ecosystem Available for Drupal 8+ but still in development For greenfield Drupal 10/11 projects, ECA generally has stronger ecosystem momentum ECA (Event-Condition-Action) Built specifically for Drupal 8+ architecture Uses modern Drupal APIs (Typed Data, Plugin system) Provides visual workflow modeling with BPMN Actively developed with regular releases Note on ECA limitations: Visual workflows become harder to maintain once business logic becomes deeply nested or computation-heavy.…