# Architecture

> Skill: Architecture (Boundaries, Dependencies, Errors)

- Skill: `melsaeed276/architecture` (Agent Skill, multi-file: 7 files)
- Install (CLI): `npx skillmds@latest add melsaeed276/architecture`
- Raw SKILL.md: https://api.skillmd.com/api/skills/melsaeed276/architecture/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: Melsaeed276 (https://skillmd.com/u/melsaeed276)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/melsaeed276/architecture

---


# Skill: Architecture (Boundaries, Dependencies, Errors)

## Purpose
Architecture keeps complexity manageable: clear boundaries between UI, domain rules, and data/platform details.
This hub routes common architecture topics for Flutter apps.

## When to use
- The codebase is inconsistent across features.
- UI, data, and business logic are tightly coupled.
- You need dependency injection or a repository layer.

## When NOT to use
- Do not over-architect small apps; start simple and add boundaries when needed.

## Core concepts
- **Boundaries**: where responsibilities change.
- **Dependency direction**: higher layers depend on lower-level abstractions.
- **Error contracts**: failures modeled consistently.

## Recommended patterns
- Use feature-first structure.
- Put interfaces in the domain layer.
- Keep DTOs in data layer; map to domain entities.

## Minimal example

Where to go next:

```text
- Folder/module consistency -> feature_structure.md
- Layering and boundaries -> clean_architecture.md
- Dependency injection -> dependency_injection.md
- Repository abstraction -> repository_pattern.md
- DTO vs entity mapping -> dto_vs_entity.md
- Typed failures -> error_modeling.md
```

## Edge cases
- Multi-brand/white-label needs config injection.
- Offline-first needs explicit caching and invalidation.

## Common mistakes
- Leaking API response shapes into UI.
- Circular dependencies between features.

## Testing strategy
- Unit test domain logic.
- Contract test repository behavior with canned data.

## Related skills
- [Data layer](../data/SKILL.md)
- [State modeling](../state/shared/state_modeling.md)
- [Testing hub](../testing/SKILL.md)