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Create robust cross-platform mobile applications using React Native with modern development patterns including navigation, state management, API integration, and native module handling.

33 React performance and composition rules across bundle optimization, re-rendering, rendering, hooks, and component patterns. \n \n Covers 6 rule categories: bundle size optimization (barrel imports, conditional loading, preloading), re-render prevention (functional setState, derived state, memoization), rendering performance (content-visibility, hydration, transitions), client patterns (passive listeners, localStorage versioning), hooks best practices (limiting useEffect, named functions), and

Establish design token hierarchies, theming infrastructure, and component architecture for scalable design systems. \n \n Covers three-layer token organization: primitive tokens (raw values), semantic tokens (contextual meaning), and component tokens (specific usage) \n Includes theme switching patterns with CSS custom properties, React context providers, system preference detection, and persistent storage \n Provides component architecture patterns including compound components, polymorphic var

When to Use: This is for when your site/app already works and looks decent and you want to improve it. There's a different approach when it looks bad and needs a complete overhaul.

Vue Pinia state management patterns, store setup guidance, and reactivity best practices. \n \n Covers store initialization, DevTools integration, and SSR considerations for setup stores \n Addresses common reactivity pitfalls including destructuring breaks and method binding issues in templates \n Provides patterns for ephemeral state like filters, URL synchronization, and production app conventions \n References specific error scenarios with linked solutions for quick troubleshooting \n

Load with: ui-web.md or ui-mobile.md

You are an experienced UI visual validation expert specializing in comprehensive visual testing and design verification through rigorous analysis methodologies.

$22

Write and review React Native component tests using Testing Library v13 and v14. \n \n Covers render patterns, screen queries (getBy/getAllBy/queryBy/findBy variants), Jest matchers, userEvent interactions, fireEvent, and async patterns with version-specific behavior \n Automatically detects your project's RNTL version (v13 for React 18, v14 for React 19+) and applies correct API signatures and sync/async rules \n Provides query priority guidance (getByRole first), interaction best practices (us

Source: fsd.how | Strictness can be adjusted based on project scale and team context.