Systematic approach to diagnose and resolve backend service issues including dependency conflicts, database schema mismatches, import errors, and middleware configuration problems in FastAPI applications.

Systematic debugging for Encore.ts backend incidents using diagnostic scripts, database queries, and structured logging. Use when backend tests fail, services crash, or async flows stall.

Your approach to handling backend deployment. Use this skill when working on files where backend deployment comes into play.

**Deep research-driven skill for finding optimal backend architectures and patterns.**

Conducts comprehensive backend design reviews covering API design quality, database architecture validation, microservices patterns assessment, integration strategies evaluation, security design review, and scalability analysis. Evaluates API specifications (REST, GraphQL, gRPC), database schemas, service boundaries, authentication/authorization flows, caching strategies, message queues, and deployment architectures. Identifies design flaws, security vulnerabilities, performance bottlenecks, and scalability issues. Produces detailed design review reports with severity-rated findings, architecture diagrams, and implementation recommendations. Use when reviewing backend system designs, validating API specifications, assessing database schemas, evaluating microservices architectures, reviewing integration patterns, or when users mention backend design review, API design validation, database design review, microservices assessment, or backend architecture evaluation.

Unified backend development skill covering API design (REST/GraphQL/tRPC), TypeScript expertise, data analysis, and code optimization principles. Use for backend architecture, API patterns, type issues, data processing, and code quality.

Comprehensive backend development workflow that orchestrates expert analysis, architecture design, implementation, and deployment using the integrated toolset. Handles everything from API design and database architecture to security implementation and DevOps automation.

Senior Backend Developer with 10+ years Java and 5+ years Spring Boot experience. Use when implementing Spring Boot features, writing Java code, creating REST APIs, working with databases (R2DBC, JPA), implementing business logic, or writing unit/integration tests.

Backend Developer Agent. 코드 개발, 디버깅, 기능 구현을 담당합니다. 개발, 코딩, 디버그(debug), 버그 수정, 기능 구현 관련 요청 시 사용됩니다.

Orchestrate end-to-end backend feature development from requirements to deployment. Use when coordinating multi-phase feature delivery across teams and services.

API design, database patterns, REST/GraphQL, microservices architecture, and backend best practices

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.

Generate production-ready REST or GraphQL endpoints with request validation, error handling, and comprehensive tests.

Build robust backend systems with modern technologies (Node.js, Python, Go, Rust), frameworks (NestJS, FastAPI, Django), databases (PostgreSQL, MongoDB, Redis), APIs (REST, GraphQL, gRPC), authentication (OAuth 2.1, JWT), testing strategies, security best practices (OWASP Top 10), performance optimization, scalability patterns (microservices, caching, sharding), DevOps practices (Docker, Kubernetes, CI/CD), and monitoring. Use when designing APIs, implementing authentication, optimizing database queries, setting up CI/CD pipelines, handling security vulnerabilities, building microservices, or developing production-ready backend systems.

Design and implement robust, production-grade backend systems with strong architecture, correctness, performance, and operational rigor. Use this skill when the user asks to build APIs, services, data pipelines, system architectures, or backend-heavy applications.

Create feature-rich PHP enums following Laravel conventions with SCREAMING_SNAKE_CASE case names, backed enum values (string or int), helper methods for labels and comparisons, validation rules, and comprehensive Pest tests. Use this skill when converting hardcoded strings or magic numbers to type-safe enums, creating categorical data types like statuses, types, roles or categories, adding enum-based validation to forms or APIs, refactoring magic strings into structured types, or defining a fixed set of allowed values in your application. This skill applies when working on files in app/Enums/ directory, creating enum classes, adding enum casts to models, or implementing enum validation rules.

Backend typed error handling and boundary mapping

Ultimate 25+ years expert-level backend skill covering FastAPI, Express, Node.js, Next.js with TypeScript. Includes ALL databases (PostgreSQL, MongoDB, Redis, Elasticsearch), ALL features (REST, GraphQL, WebSockets, gRPC, Message Queues), comprehensive security hardening (XSS, CSRF, SQL injection, authentication, authorization, rate limiting), complete performance optimization (caching, database tuning, load balancing), ALL deployment strategies (Docker, Kubernetes, CI/CD), advanced patterns (microservices, event-driven, saga, CQRS), ALL use cases (e-commerce, SaaS, real-time, high-traffic), complete testing (unit, integration, E2E, load, security). Route protection, middleware, authentication implementation in PERFECTION. Use for ANY backend system requiring enterprise-grade security, performance, scalability, and architectural excellence.

Complete FastAPI development including framework fundamentals, architecture patterns (Clean Architecture, Hexagonal Architecture, DDD), dependency injection, async patterns, and best practices. Use when implementing FastAPI endpoints, architecting backend systems, or applying architectural patterns to FastAPI applications.

Scaffolds backend features including new domain entities, new properties on existing entities, and new business operations. Use when creating a new domain entity, extending an existing entity with new properties, or adding new business features/commands.

Enforces Go backend best practices following clean architecture, dependency injection, and test-driven development. Automatically applied for Go backend implementation, API development, and microservices construction.

Diagnose and fix FastAPI hangs caused by blocking ThreadPoolExecutor shutdown in the news stream route; includes py-spy capture and non-blocking executor pattern.

Production-ready backend API implementation patterns including REST, GraphQL, authentication, error handling, and data validation

Backend Implementation Workflow Agent. Backend만 구현이 필요한 경우 사용합니다. API 추가, 서비스 로직 구현, DB 스키마 변경 등을 오케스트레이션합니다.

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Java Developer Agent. Java/Spring Boot 기반 백엔드 개발을 담당합니다. Spring, JPA, Hibernate, Maven, Gradle 전문.

Kotlin Developer Agent. Kotlin 기반 백엔드 개발을 담당합니다. Coroutines, Ktor, Spring Boot + Kotlin 전문.

Find and fix API performance bottlenecks.

Master skill for TypeScript backend development. Decision framework for APIs (tRPC/REST), authentication (Auth.js/Passport), database (Prisma), validation (Zod), logging (Pino), testing (Vitest), and deployment (Docker). Routes to specialized skills for implementation. Use as entry point for any backend task.

Create and manage database migrations with reversible changes, proper naming conventions, and zero-downtime deployment strategies. Use this skill when creating database migration files, modifying schema, adding or removing tables/columns, managing indexes, or handling data migrations. Apply when working with migration files (e.g., db/migrate/, migrations/, alembic/, sequelize migrations), schema changes, database versioning, rollback implementations, or when you need to ensure backwards compatibility during deployments. Use for any task involving database structure changes, index creation, constraint modifications, or data transformation scripts.

Create and manage database schema migrations with reversible changes, clear naming, and safe deployment practices. Use this skill when writing database migration files, modifying database schemas, creating migration scripts, or managing database version control. When working on migration files in database migration directories, files defining schema changes (CREATE TABLE, ALTER TABLE, DROP TABLE), migration rollback/down methods, database index creation scripts, seed data or data migration files, ORM migration configurations (Prisma, Drizzle, TypeORM), or files handling database versioning and migration history.

Create and manage database migrations with reversible changes, zero-downtime deployments, and proper version control. Use this skill when creating database migration files, modifying database schemas, adding or removing tables or columns, creating indexes, or managing database versioning. When working with migration files (e.g., `*_migration.rb`, `*.migration.ts`, `alembic/versions/*.py`), schema changes, or database rollback procedures. When implementing backwards-compatible database changes or separating schema migrations from data migrations.

Define database models and schemas with proper data types, constraints, relationships, and validation rules. Use this skill when creating or modifying database models, ORM entities, schema definitions, or data validation layers. When working on Prisma schema files, TypeORM entities, Drizzle schema definitions, Mongoose models, database model classes, files defining table structures and relationships, validation schemas for database entities, or files implementing data integrity constraints and cascading behaviors.

Define database models with clear naming, appropriate data types, constraints, relationships, and validation at multiple layers. Use this skill when creating or modifying database model files, ORM classes, schema definitions, or data model relationships. Apply when working with model files (e.g., models.py, models/, ActiveRecord classes, Prisma schema, Sequelize models), defining table structures, setting up foreign keys and relationships, configuring cascade behaviors, implementing model validations, adding timestamps, or working with database constraints (NOT NULL, UNIQUE, foreign keys). Use for any task involving data integrity enforcement, relationship definitions, or model-level data validation.

Define database models with clear naming, proper data types, relationships, constraints, and validation rules. Use this skill when creating or editing ORM model files, database schema definitions, model classes, or entity definitions. When working with model files (e.g., `models/*.rb`, `models/*.py`, `*.model.ts`, `entities/*.java`), defining table structures, setting up foreign keys and relationships, adding timestamps, implementing data validation, or configuring database constraints. When establishing model associations, cascade behaviors, or indexes on model attributes.

Use when designing or reviewing a backend MVP with tight budget, evolving schema, and reliance on third-party backends where idempotency, replay, and responsibility attribution are high-risk.

Node Developer Agent. Node.js/TypeScript 기반 백엔드 개발을 담당합니다. NestJS, Express, Prisma 전문.

backend-nodejs

Coordinates backend development tasks (APIs, services, databases). Use when implementing REST APIs, business logic, data models, or service integrations. Applies backend-standard.md for quality gates.

Authentication middleware for Express.js and Node.js applications. Use when building Express APIs that need JWT authentication, OAuth, or custom auth strategies. Provides 500+ authentication strategies. Choose Passport.js over Auth.js for Express backends, pure API servers, or when you need maximum control over auth flow.

Apply backend patterns for server architecture, database interactions, and API structure. Use when designing backend systems. Not for frontend logic or simple scripts.

PHP Developer Agent. Laravel 기반 백엔드 개발을 담당합니다. Eloquent ORM, Artisan, Queue, Sanctum 전문.

High-performance structured JSON logging for Node.js. Use when building production APIs that need fast, structured logs for observability platforms (Datadog, ELK, CloudWatch). Provides request logging middleware, child loggers for context, and sensitive data redaction. Choose Pino over console.log for any production TypeScript backend.

Type-safe database ORM for TypeScript/Node.js. Use when you need database access with full TypeScript integration — auto-generated types from schema, migrations, and query builder. Best for PostgreSQL, MySQL, SQLite, MongoDB. Choose Prisma over raw SQL or Knex when type safety and developer experience are priorities.

Your approach to handling backend providers. Use this skill when working on files where backend providers comes into play.

Profile and optimize Python backend code using cProfile, memory profilers, and performance best practices. Use when debugging slow FastAPI code, optimizing bottlenecks, or improving application performance.

Implement comprehensive testing strategies with pytest, fixtures, mocking, and test-driven development for FastAPI applications. Use when writing Python tests, setting up test suites, or implementing testing best practices.

backend-python

Runs formatting, linting, and tests for the backend.

Write secure, optimized database queries using parameterized statements, proper indexing, and efficient data fetching patterns. Use this skill when writing database queries, ORM query methods, SQL statements, or data access layer code. When working on files containing Prisma queries, TypeORM query builders, raw SQL statements, database transaction logic, eager loading and joins, query optimization code, files implementing data pagination or filtering, cache strategies for expensive queries, or files handling database connection pooling and query timeouts.