Go and Rust systems programming best practices for performance-critical, concurrent, and safe applications. Covers error handling, ownership/borrowing (Rust), context and goroutines (Go), testing patterns, and production deployment. Use when working with .go, .rs files, Cargo.toml, go.mod, or when asking about Go or Rust development.
Expert in code design standards including SOLID principles, Clean Code patterns (KISS, YAGNI, DRY, TDA), and pragmatic software design. **ALWAYS use when designing ANY classes/modules, implementing features, fixing bugs, refactoring code, or writing functions.** Use proactively to ensure proper design, separation of concerns, simplicity, and maintainability. Examples - "create class", "design module", "implement feature", "refactor code", "fix bug", "is this too complex", "apply SOLID", "keep it simple", "avoid over-engineering".
Backend engineering with Modular Monolith, bounded contexts, and Hono. **ALWAYS use when implementing ANY backend code within contexts, Hono APIs, HTTP routes, or service layer logic.** Use proactively for context isolation, minimal shared kernel, and API design. Examples - "create API in context", "implement repository", "add use case", "context structure", "Hono route", "API endpoint", "context communication", "DI container".
Complete 11-phase guide for building production-ready MCP (Model Context Protocol) servers with semantic layer integration. Covers foundation to deployment, including agent-centric design, tool development, testing, error handling, performance optimization, monitoring, security, governance, and semantic layer integration for business metrics. Use when building enterprise-grade MCP servers that integrate with dbt, Tableau, or other semantic layers for Finance SSC, business analytics, or data governance use cases.
Create or update CLAUDE.md with best practices - brevity, universal applicability, progressive disclosure
Expert frontend engineering with simplified pragmatic architecture, React 19, TanStack ecosystem, and Zustand state management. **ALWAYS use when implementing ANY frontend features.** Use when setting up project structure, creating pages and state management, designing gateway injection patterns, setting up HTTP communication and routing, organizing feature modules, or optimizing performance. **ALWAYS use when implementing Gateway Pattern (Interface + HTTP + Fake), Context API injection, Zustand stores, TanStack Router, or feature-based architecture.**
Architecture audit and analysis specialist for Modular Monoliths. **ALWAYS use when reviewing codebase architecture, evaluating bounded contexts, assessing shared kernel size, detecting "Core Obesity Syndrome", or comparing implementation against ADR-0001 and anti-patterns guide.** Use proactively when user asks about context isolation, cross-context coupling, or shared kernel growth. Examples - "audit contexts structure", "check shared kernel size", "find cross-context imports", "detect base classes", "review bounded context isolation", "check for Core Obesity".
Many turns in one call. Instant communication. No round-trips.
Audit code for testability design patterns. Identifies business logic entangled with IO and suggests functional core / imperative shell separation.
アーキテクチャ設計（境界/依存/データフロー/非機能/運用）を、制約とトレードオフで言語化し、ADR-liteで合意形成しながら段階的に形にする。doc/rdd.md にアーキテクチャ/非機能/運用の要求がある、または設計判断（分割/責務/インタフェース/データ整合/観測性/スケール）相談で使う。
Clean Architecture principles for Modular Monolith with bounded contexts and minimal shared kernel. **ALWAYS use when working on backend code, ESPECIALLY when creating files, deciding file locations, or organizing contexts (auth, tax, bi, production).** Use proactively to ensure context isolation and prevent "Core Obesity Syndrome". Examples - "create entity", "add repository", "where should this file go", "modular monolith", "bounded context", "shared kernel", "context isolation", "file location", "layer organization".
Factorio-style logistics — items flow automatically between containers
Error handling patterns including exceptions, Result pattern, validation strategies, retry logic, and circuit breakers. **ALWAYS use when implementing error handling in backend code, APIs, use cases, or validation logic.** Use proactively for robust error handling, recovery mechanisms, and failure scenarios. Examples - "handle errors", "Result pattern", "throw exception", "validate input", "error recovery", "retry logic", "circuit breaker", "exception hierarchy".
設計と実装を「最小で正確」に進め、TDD（RED→GREEN→REFACTOR）と差分思考で品質と速度を両立する。設計の溶け込み（責務不明/重複/暫定対応）を防ぎ、レビュー可能な変更へ落とし込むときに使う。
Provides Spring Boot API development standards. Use when implementing response formats, logging, i18n, or exception handling patterns.
Guide for quality focused software architecture. This skill should be used when users want to write code, design architecture, analyze code, in any case that relates to software development (.NET/C#).
搜索并提炼业界/开源最佳实践的 SOP，强调可信来源、适用边界与可执行建议。
Medusa.js workflow intelligence. Returns processing, refunds, order management, e-commerce workflows. Actions: design, implement, search, generate, review, optimize, debug, structure, architect, refactor workflow code. Components: workflow steps, compensation logic, hooks, modules, services, API routes, subscribers. Patterns: idempotent steps, reversible workflows, long-running tasks, saga pattern, error handling, retry logic. Topics: Medusa.js, workflow API, step functions, module architecture, database transactions, event-driven design, TypeScript, PostgreSQL, Redis. (project)
WHEN to auto-invoke: Creating API routes, building endpoints, adding route.ts files, implementing REST/GraphQL APIs, adding authentication to APIs, rate limiting, API validation with Zod, handling HTTP methods (GET/POST/PUT/DELETE). WHEN NOT to invoke: Pure frontend work, styling, React components without API calls, documentation-only tasks, database migrations without API changes.
Guidelines for building scalable, SEO-friendly applications with Next.js (App Router).
Production-grade FastAPI development with async patterns, Pydantic v2, dependency injection, ML/AI endpoint design, and modern Python best practices for building high-performance REST APIs
