Your Validation Attributes Are Hiding Business Logic

Data Annotations are fine for simple field checks, but they run out of road fast — cross-field rules, conditional logic, and anything that needs a database lookup don't fit cleanly into an attribute.

FluentValidation earns its place exactly where attributes stop being enough. The full article breaks down where that line sits and how to move validation logic somewhere it can actually be tested.

Read the full article on Medium.