Application Architecture Standard

Purpose

Single source of truth for application structure and architectural boundaries.

1. Layering Rules

Presentation Layer

• Controllers
• Form Requests (validation only)

No business logic allowed.

Application Layer

• Services
• DTOs
• Transformers

Holds all business logic orchestration.

Domain Layer

• Models Represents state and invariants only.

Infrastructure Layer

• API clients
• External services

Must be replaceable and contain no business logic.

2. Service Rules

• Business logic lives in services.
• Services must remain framework-agnostic except for Laravel infrastructure (Eloquent, DB transactions, HTTP client, logging).
• No view/UI concerns inside services.
• DTOs are used for structured data transfer where transformation, validation, or reuse is required.
• They are optional for internal service calls when validated arrays are sufficient.

3. Dependency Rules

• Constructor injection only
• No service locators
• No hidden dependencies

4. Architecture Integrity

• No cross-layer leakage
• Strict separation of concerns
• Refactoring must preserve behavior