skills

Python architecture patterns including KISS, SRP, separation of concerns, composition over inheritance, dependency injection, project structure, module organization, and public API design. Use when designing new components, organizing projects, planning directory layouts, refactoring complex code, or deciding between inheritance and composition.

Python code quality patterns including style, formatting, naming conventions, docstrings, type annotations, generics, protocols, and anti-pattern avoidance. Use when writing new code, reviewing style, configuring ruff/mypy/pyright, adding type hints, implementing generics or protocols, or reviewing code for common mistakes.

Python robustness patterns including input validation, exception hierarchies, retry logic, timeouts, and fault-tolerant decorators. Use when implementing validation, designing exception strategies, adding retry logic, handling transient failures, handling batch partial failures, or building fault-tolerant services.

Use when designing test suites, planning test coverage, choosing which layer (unit/integration/E2E) to test at, writing test cases for microservice chains, state machines, or complex business logic. Use when asking how to scope tests, how to avoid over-testing across service boundaries, or how to apply equivalence partitioning, boundary value analysis, or decision tables.

Playwright implementation reference for E2E tests: Page Object Model, auth state reuse, artifact management (screenshots/traces/video), CI/CD integration, and flaky test handling. Use when implementing Playwright tests in Python/pytest. For E2E test design strategy and scope decisions, see designing-tests skill.

Use when building Go Web projects with DDD and Clean Architecture on the github.com/go-jimu/template ecosystem. Covers: project bootstrapping with gonew, layer isolation (domain/application/infrastructure), Aggregate Roots with validation and events, Value Objects, CQRS (Commands + Queries), Domain Events via Mediator, Repository pattern with XORM, ConnectRPC API layer, fx dependency injection wiring, error handling with oops, and testing strategy. Use when: (1) creating a new Go DDD project from scratch, (2) adding a new bounded context/domain module, (3) defining entities, VOs, or repositories, (4) implementing CQRS handlers, (5) wiring fx modules, (6) writing proto/ConnectRPC APIs.

Use when a major project step has been completed and needs to be reviewed against the original plan and coding standards.

Use when designing database schemas, implementing repository patterns, writing optimized queries, managing migrations, or working with indexes and transactions for SQL/NoSQL databases.

Use when designing REST or GraphQL APIs, defining endpoints, implementing pagination/filtering, handling API versioning, or establishing API documentation with OpenAPI/Swagger.

Use when profiling Go applications (pprof), running benchmarks, optimizing memory/CPU usage, or debugging performance bottlenecks in production Go code.

Use when building Go backend services, implementing goroutines/channels, handling errors idiomatically, writing tests with testify, or following Go best practices for APIs/CLI tools.

Use when implementing React 19 features, optimizing components, or choosing between Actions vs TanStack Query for mutations. Covers React Compiler optimization, Server Actions, Forms, and new hooks.

Use when building Vue 3 applications with TypeScript, implementing Composition API components, setting up Pinia stores, or working with Vue Router. Covers script setup, composables, and reactive state.

Merge multiple video files or all videos in a directory into a single output file using ffmpeg. Use when user wants to combine clips, stitch recordings, or join video segments.

Analyzes API documentation from OpenAPI specs to provide TypeScript interfaces, request/response formats, and implementation guidance. Use when implementing API integrations, debugging API errors (400, 401, 404), replacing mock APIs, verifying data types, or when user mentions endpoints, API calls, or backend integration.

Modern React 19+ patterns with TypeScript including function components, hooks, state management, TanStack Query integration, form handling with Zod, error boundaries, and performance optimization. Use when building React applications, implementing components, or setting up state management.