Explains design system patterns including design tokens, component layers, API design, accessibility defaults, theming, documentation, and governance. Use when structuring a reusable component system, defining tokens and variants, or deciding how teams should build and evolve shared UI.
Explains browser storage patterns including cookies, localStorage, sessionStorage, and when to use each. Use when deciding how to persist client-side data, handle auth/session concerns, or choose safe storage patterns for preferences, drafts, and browser state.
Explains error handling patterns in web applications including error boundaries, retries, recovery UX, normalized error shapes, graceful degradation, and observability hooks. Use when designing how applications should fail, recover, and communicate problems to users.
Explains observability patterns for web applications including logs, metrics, traces, client error reporting, correlation IDs, SLOs, and alert design. Use when debugging production issues, designing telemetry, or deciding what signals to collect from frontend and backend systems.
Explains web performance patterns including Core Web Vitals, network and JavaScript cost, rendering and hydration work, lazy loading, caching, and performance budgets. Use when diagnosing slow pages, improving user-perceived speed, or deciding which optimization strategy matters most.
Explains testing strategy for modern web applications including unit, integration, component, end-to-end, contract, accessibility, visual, and performance testing. Use when deciding what to test at each layer, choosing modern testing tools, designing CI quality gates, or improving confidence without creating a slow and brittle test suite.
[TODO: Complete and informative explanation of what the skill does and when to use it. Include WHEN to use this skill - specific scenarios, file types, or tasks that trigger it.]
Explains accessible interaction patterns in web applications including keyboard navigation, focus management, semantic controls, form feedback, announcements, and motion preferences. Use when building interactive UI that must work well for keyboard, screen reader, and assistive technology users.