Coding standards, frameworks, refactoring, and code review (16.4K skills)
Review slow page loads and choose resource hints, browser instructions that start loading or connecting earlier. Use measurements to identify bottlenecks, then recommend preload, preconnect, prefetch, or dns-prefetch for important assets and likely next-page resources.
Review and implement loading feedback for operations such as fetching content or submitting actions. Use skeleton placeholders, spinners, and accessible status updates to communicate progress, while checking for layout shifts and measuring actual performance bottlenecks.
Audit slow page loads by measuring LCP, the time until the largest visible content appears. Identify bottlenecks in images, server responses, and rendering, then recommend changes supported by measurements.
Review whether interactive web elements work with keyboard navigation. Check Tab order, hidden elements, and focus traps where users cannot move away, then identify specific fixes and ways to verify behavior with browser accessibility tools or assistive technology.
Review links so their destinations are clear even without surrounding text. Identify vague wording, improve names announced by screen readers, and check keyboard behavior and download details such as file type and size.
Review website navigation markup so screen reader users can identify and jump between navigation areas. Check nav elements, descriptive labels, and skip links, then pinpoint issues in the HTML delivered to the browser.
Audit page loading and defer offscreen images, videos, iframes, and heavy components until needed. Use measurements and page context to identify suitable changes while keeping images needed for the initial view loaded with priority.
Review large tables, feeds, and lists for rendering overhead. Introduce virtualization, which renders only visible items and a small buffer, while preserving keyboard access, selection, and expected scrolling behavior.
Find TypeScript values that bypass type checking through any, including inferred types and assertions. Suggest unknown, generics that preserve type relationships, or Zod validation for external data, with the checks needed where each value is used.
Inspect compressed JavaScript bundles, the files that package application code, to find excessive size and loading costs. Recommend splitting code, removing unused portions, and reviewing dependencies based on measured effects on page responsiveness.
Review page landmarks, the named regions screen reader users navigate between. The skill checks semantic HTML elements, a single main content region, and labels for repeated region types, then identifies markup changes and ways to verify them.
Review TypeScript settings and indexed access to arrays and objects to find values that may be undefined. Enable compiler checks and update unsafe code so potential failures become visible before the code runs.
Audit JavaScript page redirects, confirm their impact on loading time with performance measurements, and identify where server-side 301 or 302 redirects can replace them. Get specific findings and an explanation of loading and search indexing concerns.
Review JavaScript JSON parsing for malformed input and unexpected data structures. Add error handling and validate parsed data before use, helping prevent failures when reading API responses, browser storage, or user-provided content.
Find and fix JavaScript memory leaks that accumulate as people use a web app. Review event listeners, timers, retained page elements, and outdated asynchronous tasks, then explain how to verify cleanup in the browser.
Review HTML list structure so screen readers can identify lists and announce item counts. Find list items without valid containers, check custom accessibility roles, and guide fixes to markup used for navigation or styling.
Review JavaScript loops and replace suitable ones with standard array and object methods. Make transformations, filtering, and aggregation easier to understand, with practical explanations and browser checks to confirm that changes preserve the intended behavior.
Review CSS spacing, borders, and positioning for conversion to logical properties, which follow writing direction. Check rendered layouts across screen sizes and interaction states to support right-to-left languages and vertical text.
Review JavaScript libraries for outdated versions, known security flaws, and unnecessary size. Use performance measurements to identify costly dependencies, then recommend secure updates or lighter alternatives with specific files and requests to investigate.
Audit website images and guide conversion to WebP and AVIF, formats that reduce image transfer size. Identify affected files, add fallback images, and review dimensions and loading behavior alongside the impact on initially visible content.
Review modal dialogs for keyboard and screen reader accessibility. The skill checks dialog roles, title labels, focus movement within the modal, Escape dismissal, and focus returning to the opening control, then identifies issues and ways to verify fixes.
Audit CSS class names for inconsistency and ambiguity, then organize them using BEM, a convention that names components, their elements, and variations. Check the rendered interface across screen sizes and interaction states when reviewing changes.
Check whether images visible when a page first opens are unnecessarily lazy loaded, meaning their loading is deferred. Verify rendering delays with performance measurements, then guide changes to loading attributes and request priority.
Audit JavaScript delivered to modern browsers for unnecessary older code and compatibility patches. Confirm performance costs with measurements, then review build targets and browser-specific delivery to reduce avoidable download size and processing work.