mypy

This skill provides comprehensive guidance on Python's asyncio framework for modern concurrent programming using async/await syntax. It covers core concepts like event loops, tasks, and coroutines along with practical implementations including aiohttp for async HTTP operations and FastAPI async patterns. Use it when building concurrent I/O-bound applications, parallel API clients, real-time systems, or async web servers.

This skill provides comprehensive Go observability instrumentation using OpenTelemetry for distributed tracing, Prometheus for metrics collection, and structured logging with slog. Use it when instrumenting microservices for production monitoring, debugging distributed systems, or setting up operational dashboards. It covers everything from initializing tracers and metrics endpoints to implementing HTTP middleware and health checks.

This skill provides Jest with TypeScript configuration for industry-standard testing in JavaScript/TypeScript projects. It's ideal for testing existing Jest projects, React/Node.js applications with TypeScript, and migrating JavaScript projects to TypeScript. The setup includes Jest ecosystem tools, React Testing Library integration, snapshot testing, and built-in coverage reporting.

This skill enables professional Python testing with pytest, providing fixtures, parametrization, and mocking capabilities. It's ideal for writing unit/integration tests, TDD workflows, and testing async code across frameworks like FastAPI, Django, and Flask. Developers can quickly set up tests with fixtures, use parametrization for multiple scenarios, and run comprehensive test suites.