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.

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.

backend-nodejs

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.

Write secure, optimized database queries using parameterized statements, eager loading, and proper indexing to prevent SQL injection and N+1 query problems. Use this skill when writing database queries, using ORM query methods, implementing data fetching logic, or optimizing database performance. When working with SQL queries, ORM query builders, repository patterns, or data access layers. When implementing joins, eager loading, query optimization, transactions, or query caching. When selecting data, filtering records, or fetching related associations in service files, repository files, or controller methods.

Supabase schema validation, RLS enforcement, and API security best practices.

Expert in secure backend coding practices specializing in input

**Philosophy: Simple, bug-free, maintainable code. Zero complexity for complexity's sake.**

提供后端开发、API 设计、数据库交互和框架特定开发能力。当需要实现后端功能、设计 API 或处理数据层逻辑时使用。

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

Backend TDD Agent. Node.js/NestJS 기반 TDD 테스트 작성 및 구현을 담당합니다. 테스트 먼저 작성 후 구현하는 Red-Green-Refactor 사이클을 따릅니다.

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Use when generating tests for backend code (Express routes, MongoDB models, Node services) - analyzes file type, detects test framework from package.json, generates comprehensive tests with setup/teardown and edge case coverage

Generate comprehensive backend tests with Jest/Vitest including fixtures and mocks.

Run isolated test environments for backend changes, manage test data, and verify API endpoints. Use when testing Python backend changes without interfering with production instances.

Write and review backend tests with JUnit5, MockMvc, and Spring Boot Test. Use for writing controller tests, service tests, and integration tests.

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

Generate OpenAPI/REST endpoints from tRPC routers. Use when you have a tRPC API but need to expose REST endpoints for third-party integrations, mobile apps, or public API documentation. Provides automatic Swagger UI and OpenAPI spec generation. Choose this when you want type-safe internal APIs (tRPC) with REST fallback for external consumers.

Type-safe API layer for TypeScript full-stack applications. Use when building APIs that need end-to-end type safety between client and server WITHOUT code generation. Ideal for Next.js, React, and Express apps where both frontend and backend are TypeScript. Choose tRPC over REST/GraphQL when you control both ends and want zero runtime overhead for type checking.

Automatically runs required Go checks after any backend code changes. Ensures go vet, gofmt, and go test pass before commits. Use whenever modifying files in the backend/ directory.

Fast unit testing framework for TypeScript/JavaScript. Use for testing tRPC procedures, Zod schemas, utility functions, and any TypeScript code. Built on Vite with native ESM, TypeScript support, and Jest-compatible API. Choose Vitest over Jest for modern TypeScript projects, especially with Vite-based setups.

Backfill missing GitHub streak dates using the streakify.sh script. Use this when the user asks to backfill dates, fix missing streak days, or catch up on streak commits.

To read logs from a managed background process, fetch recent output (head or tail) for a process so you can inspect its stdout/stderr.

Maintain a lightweight backlog of high-value tasks discovered during work.

Expert backlog manager that prioritizes work using multi-criteria scoring, analyzes dependencies, and recommends optimal next tasks. Activates when managing backlogs, prioritizing work, adding items, or analyzing what to work on next.

Use this skill when creating or editing issues on Github or when asked to write user-stories or record bugs.

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Quick reference for Backlog.md CLI with critical file naming rules and workflow patterns

Bulk backlog scanner that analyzes the entire finans codebase vs CLAUDE.md, identifies ALL gaps, and generates a comprehensive, prioritized, numbered task backlog. Uses broad→narrow pattern.

Help backport PRs to release branches using the backport CLI tool. Use when backporting changes that have merge conflicts requiring manual resolution.

Manage data flow when producers outpace consumers. Bounded buffers, adaptive flushing, and graceful degradation prevent OOM crashes and data loss.

Build Backstage backend plugins with createBackendPlugin and core services: DI, httpRouter, secure-by-default auth, Knex DB, routes, testing. Use for APIs and background jobs.

Build Backstage frontend plugins with the new Frontend System: createFrontendPlugin, blueprints, routes, Utility APIs, testing. Use for pages, nav, entity content, or cards.

Generate enterprise-grade web applications using Backstage Design System. Create admin dashboards, developer tools, and internal applications with modern React components, dark/light themes, and responsive design patterns based on Radix UI and Tailwind CSS.

BackstopJS visual regression testing for self-hosted visual comparison

Backtest results interpreter and strategy evaluator. Analyzes historical backtest performance, identifies strengths/weaknesses, and provides actionable recommendations for strategy improvement.

Critical fix for backtest capital accounting when equity curves are inflated or drawdown metrics are meaningless

Converting backtest visualizations from bar indices/timesteps to actual datetime axes for clearer time context

Save backtest results to SQLite database for comparison. Trigger when: (1) tracking backtest history, (2) comparing model performance, (3) querying best backtests.