django-models

Business logic belongs in models and managers, not views. Views orchestrate workflows; models implement domain behavior. This principle creates testable, reusable code that stays maintainable as complexity grows.

Good: Model methods handle business rules, state transitions, validation Bad: Views contain if/else logic for domain rules, calculate derived values

Custom QuerySet classes are your secret weapon. They make queries reusable, chainable, and testable.

Django 模型設計模式強調胖模型/瘦視圖、QuerySet 最佳化和領域邏輯封裝。在設計模型、最佳化查詢、實現業務邏輯或使用 ORM 時使用。 來源：kjnez/claude-code-django。