Type & Validation Patterns

This is a plain Next.js app — no NestJS, no monorepo, no class-based DTOs.

Split per module

Each module owns its types and validation:

modules/[name]/
├── [name].types.ts       ← plain TypeScript interfaces/types
└── [name].validation.ts  ← Zod schemas for API boundary validation

Types ([name].types.ts)