Frontend

Optimize application performance through code splitting, lazy loading, caching strategies, bundle size reduction, render optimization, and profiling. Use when improving page load times, reducing bundle sizes, optimizing React rendering, implementing code splitting, configuring caching strategies, lazy loading components and routes, optimizing images and assets, profiling performance bottlenecks, implementing virtual scrolling for large lists, or improving Core Web Vitals and Lighthouse scores.

World-class design system with extensible business type registry. Automatically selects appropriate design patterns based on business context. Anti-AI detection, trend-aware, production-ready design decisions. CRITICAL: Must be read before any UI creation task.

Establish and enforce coding standards, best practices, and architectural patterns across the codebase using linters, formatters, and code review processes. Use when setting up ESLint/Prettier, configuring linting rules, creating code style guides, implementing pre-commit hooks, establishing naming conventions, enforcing TypeScript strict mode, maintaining consistency, conducting architecture reviews, or defining team coding standards.

Creates production-ready UI immediately from any description. Generates complete pages, components, and realistic mock data in FIRST response. Uses Next.js 14 + Tailwind + shadcn/ui. Never asks questions - infers everything from context. Triggers: UI creation, page building, component generation, build interface, screen design, layout requests.

Design robust error handling strategies including try-catch blocks, custom error classes, error boundaries, graceful degradation, and comprehensive logging. Use when implementing exception handling, creating custom error types, setting up error boundaries in React, designing error response formats for APIs, implementing retry logic, handling async errors and promise rejections, logging errors for monitoring, creating user-friendly error messages, or building fault-tolerant systems that fail gracefully.

Deploy and optimize applications on Vercel with preview deployments, edge functions, environment variables, and performance monitoring. Use when deploying Next.js applications, setting up preview deployments per pull request, configuring environment variables, using Vercel Edge Functions, optimizing build performance, implementing redirects and rewrites, configuring custom domains, or monitoring application performance with Vercel Analytics.

Create interactive, self-contained artifacts like mini-apps, visualizations, calculators, and tools that can be embedded or used standalone. Use when building interactive calculators, creating data visualizations, making mini web apps, building embeddable widgets, creating interactive demos, making tools for specific tasks, or generating standalone HTML/JS applications.

Implement real-time features using Convex reactive queries that automatically update when data changes, enabling live collaboration, instant updates, and reactive UIs without manual polling. Use when building live dashboards, implementing collaborative editing, creating chat applications, showing real-time notifications, building activity feeds, implementing presence indicators, creating reactive search, or any feature requiring instant data synchronization across clients.

Adds logic, state management, TypeScript types, and CRUD operations to UI. Works AFTER ui-first-builder creates the interface. Implements Zustand stores, form handling with React Hook Form + Zod, and prepares for backend connection. Triggers: add logic, add functionality, make it work, state management, form validation, data operations, TypeScript types.

Use when creating/writing/building OpenRewrite recipes, working with .java recipe files, RewriteTest files, recipe YAML files, LST visitors, JavaTemplate, visitor patterns, or when discussing recipe types (declarative YAML, Refaster templates, imperative Java recipes) - guides creation of OpenRewrite recipes for automated code transformations, AST manipulation, custom refactoring rules, and code migration.

Create visual designs, graphics, and layouts using HTML Canvas API or design tools for data visualization, graphics, animations, and interactive visual content. Use when creating data visualizations, building interactive graphics, implementing drawing tools, creating charts and diagrams, building game graphics, implementing image manipulation, or creating dynamic visual content.

Create comprehensive technical documentation including API docs, component libraries, README files, architecture diagrams, and developer guides using tools like JSDoc, Storybook, or Docusaurus. Use when documenting APIs, creating component documentation, writing README files, generating API references, documenting architecture decisions, creating onboarding guides, maintaining changelogs, documenting configuration options, or building developer documentation sites.

Build beautiful, accessible UI components using shadcn/ui library with Radix UI primitives and Tailwind CSS styling that you own and can customize. Use when creating accessible component libraries, implementing common UI patterns (dialogs, dropdowns, tooltips), building forms with validation, creating data tables, implementing command palettes, using Radix UI primitives, customizing components with Tailwind, or building design systems with full ownership of code.

Create consistent, scalable design systems using Tailwind CSS utility classes with custom themes, design tokens, and responsive design patterns. Use when building design systems, implementing custom themes, creating reusable utility patterns, configuring Tailwind theme extensions, implementing dark mode, building responsive layouts, creating design tokens, using arbitrary values, or establishing consistent spacing and typography scales.

Use Neon serverless Postgres with branching, connection pooling, and instant scalability for modern applications with Prisma or Drizzle ORM integration. Use when setting up serverless Postgres databases, implementing database branching for preview environments, configuring connection pooling, optimizing for serverless cold starts, using Prisma with Neon, implementing database migrations, scaling databases automatically, or building applications on Vercel/Netlify with Postgres.

Build modern Next.js 13+ applications using App Router architecture with Server Components, Client Components, and advanced routing patterns. Use when implementing server-first rendering, creating nested layouts, building parallel routes, implementing intercepting routes, using React Server Components, optimizing data fetching with server-side async components, implementing streaming with Suspense, managing client-side interactivity boundaries, or leveraging Next.js 13+ app directory features for performant, SEO-friendly React applications.

Implement test-driven development (TDD) workflow using the red-green-refactor cycle. Use when writing new features, fixing bugs, or refactoring existing code. Always write the failing test first, then implement minimal code to pass, then refactor. Essential for ensuring code reliability, preventing regressions, improving design through testability requirements, documenting expected behavior through tests, enabling confident refactoring, and maintaining high code quality standards throughout the development process.

Build efficient React applications using Next.js Server Components that render on the server, reducing client bundle size, improving performance, and enabling direct database access. Use when fetching data server-side, reducing JavaScript bundle size, accessing databases directly in components, implementing streaming with Suspense, creating layouts that only render once, optimizing Core Web Vitals, or building SEO-friendly applications with server-first architecture.

Design systematic decision frameworks for selecting appropriate AI tools (Claude Code vs Gemini CLI)based on context requirements, codebase size, reasoning depth needs, and task complexity. Use thisskill when starting projects with unclear tool requirements, optimizing context-constrained workflows,or designing multi-phase strategies that leverage multiple tools' strengths. This skill helps matchtool capabilities to task characteristics, preventing wasted context and ensuring optimal resourceallocation.

Generate 50-question interactive quizzes using the Quiz component with randomized batching. Use when creating end-of-chapter assessments. Displays 15-20 questions per session with immediate feedback. NOT for static markdown quizzes.