frontend-ui-engineering
Component architecture, design systems, state management, responsive design, WCAG 2.1 AA accessibility. Use when building or modifying user-facing interfaces.
What this skill does
# Frontend UI Engineering ## Overview Build user interfaces with component architecture, design system consistency, responsive design, and WCAG 2.1 AA accessibility as default requirements. Frontend work is not complete until it is accessible, responsive, and consistent. ## When to Use - Building new UI components or pages - Modifying existing user-facing interfaces - Implementing design system changes - Adding interactive features or state management ## Core Principles ### Component Architecture - Components should have a single responsibility - Prefer composition over inheritance - Keep components small: 200-400 lines typical, 800 max - Extract shared logic into hooks or utilities - Colocate styles, tests, and component code ### Design System Consistency - Use existing design tokens and variables - Follow established naming conventions - Maintain spacing, typography, and color consistency - Extend the design system rather than one-off styles ### State Management - Keep state as local as possible - Lift state only as high as needed - Use the simplest state management that works - Prefer immutable state updates ### Responsive Design - Design mobile-first by default - Use relative units (rem, em, %) over fixed pixels - Test at standard breakpoints (320px, 768px, 1024px, 1440px) - Ensure touch targets meet minimum 44x44px ### Accessibility (WCAG 2.1 AA) - All interactive elements must be keyboard accessible - Images must have alt text - Color contrast must meet 4.5:1 for text, 3:1 for large text - Forms must have associated labels - Dynamic content must have appropriate ARIA attributes - Focus management must follow logical order ## Process ### Step 1: Review Existing Patterns - Check the component library for existing solutions - Follow established file structure and naming - Use existing design tokens ### Step 2: Build Accessible First - Start with semantic HTML - Add ARIA attributes where semantic HTML is insufficient - Verify keyboard navigation works - Test with a screen reader if available ### Step 3: Make It Responsive - Implement mobile layout first - Add breakpoints for larger screens - Test at all standard widths ### Step 4: Test - Unit tests for component behavior - Visual regression tests if available - Accessibility audit with automated tools - Manual keyboard navigation test ## Common Rationalizations | Rationalization | Reality | |---|---| | "Accessibility can be added later" | Retrofitting accessibility is much more expensive than building it in. | | "This is an internal tool, accessibility does not matter" | Internal tools benefit from keyboard navigation and screen reader support too. | | "The design system is too restrictive" | Consistency speeds up both development and user comprehension. | ## Verification - [ ] Component follows existing patterns and design tokens - [ ] Keyboard navigation works for all interactive elements - [ ] Color contrast meets WCAG 2.1 AA standards - [ ] Responsive at standard breakpoints - [ ] Automated accessibility audit passes ## Anti-Rationalization Table | Excuse | Counter | |--------|---------| | "Accessibility can be added later" | Retrofitting accessibility is much more expensive than building it in. | | "This is an internal tool, accessibility doesn't matter" | Internal tools benefit from keyboard navigation and screen reader support too. | | "The design system is too restrictive" | Consistency speeds up both development and user comprehension. | | "I'll test responsive design on my phone" | Test at all standard breakpoints, not just one device. | | "The component looks good, it's done" | Visual correctness is not functional correctness. Test keyboard nav and screen readers. |
Related in Design
contribute
IncludedLocal-only OSS contribution command center. Auto-refreshes the user's in-flight PR and issue state on invoke so conversations start with full context — no need to brief Claude on what's in flight. Helps the user find issues to contribute to on GitHub, builds per-repo dossiers of what each upstream expects (CLA, DCO, branch convention, AI policy, draft-first, review bots, issue templates), runs deterministic gates before any external action so AI-assisted contributions don't reach maintainers as slop. State is markdown-only: candidate files at ~/.contribute-system/candidates/, repo dossiers at ~/.contribute-system/research/, append-only event log at ~/.contribute-system/log.jsonl. No database, no cloud calls. Use when the user asks about their PRs / issues / contributions, wants to find new work to take on, claim an issue, build/refresh a repo's dossier, or draft a Design Issue or PR. Trigger with "/contribute", "what's my PR status", "find a contribution", "claim issue X", "draft a Design Issue for Y", "refresh dossier for Z".
architectural-analysis
IncludedUser-triggered deep architectural analysis of a codebase or scoped subtree across eight modes — information architecture, data flow, integration points, UI surfaces, interaction patterns, data model, control flow, and failure modes. This skill should be used when the user asks to "diagram this codebase," "map the architecture," "show the data flow," "give me an ERD," "trace control flow," "find the integration points," "verify the layout pattern," "audit the UX architecture," or any similar request whose primary deliverable is mermaid diagrams plus cited reports under docs/architecture/. Dispatches haiku/sonnet sub-agents in parallel for per-mode exploration, then verifies every citation mechanically before any node lands in a diagram. Not for one-off prose explanations of code (use code-explanation) or for high-level system design from scratch (use system-design).
mcp
IncludedModel Context Protocol (MCP) server development and tool management. Languages: Python, TypeScript. Capabilities: build MCP servers, integrate external APIs, discover/execute MCP tools, manage multi-server configs, design agent-centric tools. Actions: create, build, integrate, discover, execute, configure MCP servers/tools. Keywords: MCP, Model Context Protocol, MCP server, MCP tool, stdio transport, SSE transport, tool discovery, resource provider, prompt template, external API integration, Gemini CLI MCP, Claude MCP, agent tools, tool execution, server config. Use when: building MCP servers, integrating external APIs as MCP tools, discovering available MCP tools, executing MCP capabilities, configuring multi-server setups, designing tools for AI agents.
react-native-skia
IncludedDesign, build, debug, and optimise high-polish animated graphics in React Native or Expo using @shopify/react-native-skia, Reanimated, and Gesture Handler. Use when the user wants canvas-driven UI, shaders, paths, rich text, image filters, sprite fields, Skottie, video frames, snapshots, web CanvasKit setup, or performance tuning for custom motion-heavy elements such as loaders, hero art, cards, charts, progress indicators, particle systems, or gesture-driven surfaces. Also use when the user asks for fluid, glow, glass, blob, parallax, 60fps/120fps, or GPU-friendly animated effects in React Native, even if they do not explicitly say "Skia". Do not use for ordinary form/layout work with standard views.
plaid
IncludedProduct Led AI Development — guides founders from idea to launched product. Six capabilities: Idea (discover a product idea), Validate (pressure-test the idea against fatal flaws, problem reality, competition, and 2-week MVP feasibility), Plan (vision intake + document generation), Design (translate image references into a design.md spec), Launch (go-to-market strategy), and Build (roadmap execution). Use when someone says "PLAID", "plaid idea", "help me find an idea", "product idea", "idea from my business", "idea from my expertise", "plaid validate", "validate my idea", "pressure-test", "is this idea good", "find fatal flaws", "validate the problem", "plan a product", "define my vision", "generate a PRD", "product strategy", "plaid design", "design from image", "translate image to design", "create design.md", "extract design tokens", "plaid launch", "go-to-market", "launch plan", "GTM strategy", "launch playbook", "plaid build", "build the app", "start building", or "execute the roadmap".
nextjs-framer-motion-animations
IncludedAdds production-safe Motion for React or Framer Motion animations to Next.js apps, including reveal, hover and tap micro-interactions, whileInView, stagger, AnimatePresence, layout and layoutId transitions, reorder, scroll-linked UI, and lightweight route-content transitions. Use when the user asks to add, refactor, or debug Motion or Framer Motion in App Router or Pages Router codebases, especially around server/client boundaries, reduced motion, LazyMotion, bundle size, hydration, or route transitions. Avoid for GSAP-style timelines, WebGL or 3D scenes, heavy scroll storytelling, or CSS-only effects unless Motion is explicitly requested.