React Router Best Practices

Proactively apply when creating design systems, component libraries, or any frontend application. Triggers on CSS Grid, Subgrid, Flexbox, Container Queries, :has(), @layer, @scope, CSS nesting, @property, @function, if(), oklch, color-mix, light-dark, relative color, @starting-style, scroll-driven animations, view transitions, anchor positioning, popover, customizable select, content-visibility, logical properties, text-wrap, interpolate-size, clamp, field-sizing, modern CSS, CSS architecture, responsive design, dark mode, theming, design tokens, cascade layers. Use when writing CSS for any web project, choosing layout approaches, building responsive components, implementing dark mode or theming, creating animations or transitions, styling form elements, or modernizing legacy stylesheets. Modern CSS features and best practices for building interfaces with pure native CSS.

Production backend systems development. Stack: Node.js/TypeScript, Python, Go, Rust | NestJS, FastAPI, Django, Express | PostgreSQL, MongoDB, Redis. Capabilities: REST/GraphQL/gRPC APIs, OAuth 2.1/JWT auth, OWASP security, microservices, caching, load balancing, Docker/K8s deployment. Actions: design, build, implement, secure, optimize, deploy, test APIs and services. Keywords: API design, REST, GraphQL, gRPC, authentication, OAuth, JWT, RBAC, database, PostgreSQL, MongoDB, Redis, caching, microservices, Docker, Kubernetes, CI/CD, OWASP, security, performance, scalability, NestJS, FastAPI, Express, middleware, rate limiting. Use when: designing APIs, implementing auth/authz, optimizing queries, building microservices, securing endpoints, deploying containers, setting up CI/CD.

Provides domain-specific best practices for Node.js development with TypeScript, covering type stripping, async patterns, error handling, streams, modules, testing, performance, caching, logging, and more. Use when setting up Node.js projects with native TypeScript support, configuring type stripping (--experimental-strip-types), writing Node 22+ TypeScript without a build step, or when the user mentions 'native TypeScript in Node', 'strip types', 'Node 22 TypeScript', '.ts files without compilation', 'ts-node alternative', or needs guidance on error handling, graceful shutdown, flaky tests, profiling, or environment configuration in Node.js. Helps configure tsconfig.json for type stripping, set up package.json scripts, handle module resolution and import extensions, and apply robust patterns across the full Node.js stack.

JavaScript performance optimization guidelines. Use when writing, reviewing, or refactoring JavaScript/TypeScript code to ensure optimal performance patterns. Triggers on tasks involving loops, data structures, DOM manipulation, or general JS optimization.

Scaffold an editable Tandem control panel app

Create distinctive, production-grade frontend interfaces with high design quality. Provides analysis tools for auditing existing designs and generation tools for creating color palettes, typography systems, design tokens, and component templates. Supports React, Vue, Svelte, and vanilla HTML/CSS. Use when building web components, pages, or applications. Keywords: design, UI, frontend, CSS, components, palette, typography, tokens, accessibility.