Frontend

Build end-to-end automated tests that simulate real user interactions across the full application stack. Use for E2E test, Selenium, Cypress, Playwright, browser automation, and user journey testing.

Manage application state using Redux, MobX, Zustand, and Context API. Use when centralizing state for complex applications with multiple components.

Build recommendation systems using collaborative filtering, content-based filtering, matrix factorization, and neural network approaches

Create comprehensive developer onboarding documentation including setup guides, README files, contributing guidelines, and getting started tutorials. Use when onboarding new developers or creating setup documentation.

Implement WCAG 2.1/2.2 accessibility standards, screen reader compatibility, keyboard navigation, and a11y testing. Use when building inclusive web applications, ensuring regulatory compliance, or improving user experience for people with disabilities.

UI/UX design intelligence. 50 styles, 21 palettes, 50 font pairings, 20 charts, 8 stacks (React, Next.js, Vue, Svelte, SwiftUI, React Native, Flutter, Tailwind). Actions: plan, build, create, design, implement, review, fix, improve, optimize, enhance, refactor, check UI/UX code. Projects: website, landing page, dashboard, admin panel, e-commerce, SaaS, portfolio, blog, mobile app, .html, .tsx, .vue, .svelte. Elements: button, modal, navbar, sidebar, card, table, form, chart. Styles: glassmorphism, claymorphism, minimalism, brutalism, neumorphism, bento grid, dark mode, responsive, skeuomorphism, flat design. Topics: color palette, accessibility, animation, layout, typography, font pairing, spacing, hover, shadow, gradient.

Structure Vue 3 applications using Composition API, component organization, and TypeScript. Use when building scalable Vue applications with proper separation of concerns.

Implement reactive programming patterns using RxJS, streams, observables, and backpressure handling. Use when building event-driven UIs, handling async data streams, or managing complex data flows.

Design property-based tests that verify code properties hold for all inputs using automatic test case generation. Use for property-based, QuickCheck, hypothesis testing, generative testing, and invariant verification.

Reduce JavaScript and CSS bundle sizes through code splitting, tree shaking, and optimization techniques. Improve load times and overall application performance.

Implement form validation using React Hook Form, Formik, Vee-Validate, and custom validators. Use when building robust form handling with real-time validation.

Organize CSS using BEM, SMACSS, and CSS-in-JS patterns. Use when building scalable, maintainable styling systems with proper naming conventions.

Evaluate test suite quality by introducing code mutations and verifying tests catch them. Use for mutation testing, test quality, mutant detection, Stryker, PITest, and test effectiveness analysis.

Prevent SQL injection attacks using prepared statements, parameterized queries, and input validation. Use when building database-driven applications securely.

Implement secure webhook systems for event-driven integrations, including signature verification, retry logic, and delivery guarantees. Use when building third-party integrations, event notifications, or real-time data synchronization.

Implement WCAG compliance using semantic HTML, ARIA, keyboard navigation, and screen reader support. Use when building inclusive applications for all users.

Implement comprehensive frontend testing using Jest, Vitest, React Testing Library, and Cypress. Use when building robust test suites for UI and integration tests.

Development cycle validation gate (Gate 5) - validates all acceptance criteria are metand requires explicit user approval before completion.

Implement real-time functionality using WebSockets, Server-Sent Events (SSE), or long polling. Use when building chat applications, live dashboards, collaborative editing, notifications, or any feature requiring instant updates.

Implement webhook systems for event-driven integration with retry logic, signature verification, and delivery guarantees. Use when creating event notification systems, integrating with external services, or building event-driven architectures.