Design e Frontend

Generate Jest unit tests for JavaScript/TypeScript with mocking, coverage. Use for JS/TS modules, React components, test generation, or encountering missing coverage, improper mocking, test structure errors.

SQL query optimization for PostgreSQL/MySQL with indexing, EXPLAIN analysis. Use for slow queries, N+1 problems, missing indexes, or encountering sequential scans, OFFSET pagination, temp table spills, inefficient JOINs.

Secure dependency upgrades with supply chain protection, cooldowns, and staged rollout. Use when upgrading deps, configuring security policies, or preventing supply chain attacks.

TanStack Table v8 headless data tables with server-side features for Cloudflare Workers + D1. Use for pagination, filtering, sorting, virtualization, or encountering state management, TanStack Query coordination, URL sync errors.

Automate 7-phase feature development with specialized agents (code-explorer, code-architect, code-reviewer). Use for multi-file features, architectural decisions, or encountering ambiguous requirements, integration patterns, design approach errors.

TanStack AI (alpha) provider-agnostic type-safe chat with streaming for OpenAI, Anthropic, Gemini, Ollama. Use for chat APIs, React/Solid frontends with useChat/ChatClient, isomorphic tools, tool approval flows, agent loops, multimodal inputs, or troubleshooting streaming and tool definitions.

Implements API rate limiting using token bucket, sliding window, and Redis-based algorithms to protect against abuse. Use when securing public APIs, implementing tiered access, or preventing denial-of-service attacks.

Validate test effectiveness with mutation testing using Stryker (TypeScript/JavaScript with Vitest or bun test via @hughescr/stryker-bun-runner) and mutmut (Python). Find weak tests that pass despite code mutations. Use to improve test quality.

Design microservices architectures with service boundaries, event-driven communication, and resilience patterns. Use when building distributed systems, decomposing monoliths, or implementing microservices.

Designs responsive interfaces starting from mobile screens with progressive enhancement for larger devices. Use when building responsive websites, optimizing for mobile users, or implementing adaptive layouts.

Use for bun:test syntax, assertions, describe/it, test.skip/only/each, and basic patterns.

Cloudflare Workers Runtime APIs including Fetch, Streams, Crypto, Cache, WebSockets, and Encoding. Use for HTTP requests, streaming, encryption, caching, real-time connections, or encountering API compatibility, response handling, stream processing errors.