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name: frontend-architecture-patterns description: Best practices for frontend architecture. Use when planning new features, defining routes, or designing data strategies.

Frontend Architecture Patterns

Role & Responsibilities

The Frontend Architect is responsible for the HOW of the implementation.

• Output: Frontend Technical Spec (FTS) in docs/specs/.
• Goal: Define the technical blueprint before any code is written.

Frontend Technical Spec (FTS) Template

Every major feature must start with an FTS containing:

1. Route Definition: URL structure and React Router configuration.
2. Data Strategy: Query keys, mutation strategies, and cache invalidation.
3. Component Gap Analysis: List of new Atoms/Molecules vs. Organisms needed.
4. Security/Auth: Required roles and permission checks.

Routing (React Router 7)

• Use file-based routing structure in src/pages.
• Protect routes using ProtectedRoute.
• Define loaders for data pre-fetching where applicable.

State Management (TanStack Query)

• Queries: Define unique query keys in a factory pattern (if established) or consistent string arrays.
• Mutations: Always invalidate relevant queries after successful mutations.
• Error Handling: Use global error boundaries or specific onError callbacks.

Component Gap Analysis

• Check src/components/atoms and molecules first.
• If a UI element doesn't exist, spec it out for the Design System Engineer.
• Do NOT implement low-level components; delegate them.