Backend

Game server architecture, scalability, matchmaking, and backend systemsfor online games. Build robust, scalable multiplayer infrastructure.

Create separate documentation that preserves discovered intent from historical investigation so future readers benefit from your research. Use when: (1) completing code archaeology investigation and needing to ensure discoveries benefit future developers facing the same confusion, (2) recurring questions from team members signal that institutional knowledge needs capture in ADRs or documentation files, (3) team member departure would take critical undocumented context about design decisions with them, (4) creating onboarding documentation where critical context exists only in git history or senior engineers' memories

Generates a Laravel architecture based on best practices for modern Laravel applications.

Maintains documentation files (README.md, .claude/claude.md, .claude/agent.md, API docs) for Unite-Hub. Ensures docs stay in sync with codebase changes. Uses Haiku model for cost-effective documentation generation.

Use when writing or updating documentation - generates function docs, API specs, architecture diagrams (Mermaid), READMEs, code explanations. Activates when user says "document this", "write README", "explain this code", mentions "docs", "documentation", "API docs", or asks "how does this work?".

Design and implement domain entities, DTOs, and data transfer objects following the project's domain-driven design patterns. Use this skill when creating or modifying domain entity classes in shared/domain/, DTO classes in features/{feature}/dto/, entity mappers in shared/mapper/, or shared type interfaces in packages/shared/types/src/dto/. This includes implementing the static factory pattern (Entity.create()), writing DTO validation decorators (class-validator), creating response DTOs with static from() methods, and defining shared interfaces that API DTOs must implement. Apply when working with @imkdw-dev/types package interfaces, ArticleContent value objects, or any file ending in .dto.ts, domain entities, or mapper classes.

This skill should be used when the user asks to "work with polars", "create a dataframe", "use lazy evaluation", "migrate from pandas", "optimize data pipelines", "read parquet files", "group by operations", or needs guidance on Polars DataFrame operations, expression API, performance optimization, or data transformation workflows.

Scaffold and automate Grafana plugin projects using @grafana/create-plugin. Use when creating panel plugins, data source plugins, app plugins, or backend plugins. Handles project scaffolding, Docker dev environment setup, and plugin configuration.

Master backend development with Node.js, Python, Java, Go, Rust, API design, databases, and microservices. Use when building APIs, designing systems, or learning backend frameworks.

Apply when implementing API authentication: JWT tokens, session management, API keys, and auth middleware. Follows JWT Best Current Practices (RFC 8725).

Python FastAPI development with uv package manager, modular project structure, SQLAlchemy ORM, and production-ready patterns.

Production patterns for Axum 0.8.x HTTP services with Tower middleware, type-safe routing, state management with FromRef, extractors, and error handling. Use when building REST APIs, HTTP services, web applications, or adding middleware to Axum routers.

World-class creation of valid, beautiful, and accessible Mermaid diagrams. Use when users request diagrams, flowcharts, sequence diagrams, entity relationship diagrams, state machines, Gantt charts, class diagrams, or any visual representation that can be expressed in Mermaid syntax. Handles all Mermaid diagram types with expert knowledge of syntax, styling, and best practices.

Secure Spring Boot applications - authentication, authorization, OAuth2, JWT, CORS/CSRF protection

Implement payment integrations with SePay (Vietnamese payment gateway with VietQR, bank transfers, cards) and Polar (global SaaS monetization platform with subscriptions, usage-based billing, automated benefits). Use when integrating payment processing, implementing checkout flows, managing subscriptions, handling webhooks, processing bank transfers, generating QR codes, automating benefit delivery, or building billing systems. Supports authentication (API keys, OAuth2), product management, customer portals, tax compliance (Polar as MoR), and comprehensive SDK integrations (Node.js, PHP, Python, Go, Laravel, Next.js). | Sử dụng khi: thanh toán, Stripe, PayPal, checkout, đăng ký, subscription.

Build production Spring Boot applications - REST APIs, Security, Data, Actuator

Manages GitHub issue parent-child relationships and sub-issues using REST and GraphQL APIs. Use when breaking down large work into Epics/Features/Tasks, creating work breakdown structures, converting markdown checklists to sub-issues, reordering sub-issues, or querying issue hierarchies. Handles ID confusion between REST numeric IDs and GraphQL node IDs.

Define shared domain types and API contracts for F# full-stack applications.Use when: "define types", "create entity", "add model", "API contract", "shared types","domain model", "record", "discriminated union", "data structure", "DTO","interface", "type definition", "new entity", "modify types".Creates types in src/Shared/Domain.fs and API interfaces in src/Shared/Api.fs.Always start here when adding new features.

Comprehensive code quality validation using Solargraph, Sorbet, and Rubocop for A+ Rails code. Trigger keywords: quality gates, validation, solargraph, sorbet, rubocop, type checking, linting, code quality, static analysis

Natural language wrapper for code review - automatically triggers /code-review when users express intent to review code, check for bugs, or validate code quality