Design

Use when FastAPI validation with Pydantic models. Use when building type-safe APIs with robust request/response validation.

Use when eSLint built-in rules including rule configuration, severity levels, and disabling strategies.

Use when working with Maven build phases, goals, profiles, or customizing the build process for Java projects.

Use when building reliable and scalable distributed systems.

Use when protocol-oriented programming in Swift including protocol extensions, default implementations, protocol composition, associated types, and designing flexible, reusable abstractions that favor composition over inheritance.

Use when functional programming patterns in Scala including higher-order functions, immutability, pattern matching, algebraic data types, monads, for-comprehensions, and functional composition for building robust, type-safe applications.

Use when scala collections including immutable/mutable variants, List, Vector, Set, Map operations, collection transformations, lazy evaluation with views, parallel collections, and custom collection builders for efficient data processing.

Use when building reusable component patterns with Tailwind CSS. Covers component extraction, @apply directive, and composable design patterns.

Use when scala's advanced type system including generics, variance, type bounds, implicit conversions, type classes, higher-kinded types, path-dependent types, and abstract type members for building type-safe, flexible APIs.

This skill should be used when running .NET tests selectively with a build-first, test-targeted workflow. Use it for running tests with xUnit focus.

Use when ruboCop cops including built-in cops, configuration, auto-correction, and development.

Expert guidance for using the GitLab CLI (glab) to manage GitLab issues, merge requests, CI/CD pipelines, repositories, and other GitLab operations from the command line. Use this skill when the user needs to interact with GitLab resources or perform GitLab workflows.

Use when creating or modifying GitHub Actions workflow files. Provides guidance on workflow syntax, triggers, jobs, steps, and expressions for creating valid GitHub Actions workflows that can be tested locally with act.

Use when applying encapsulation and information hiding principles in object-oriented design. Use when controlling access to object state and behavior.

Use when querying data with Ecto.Query DSL including where clauses, joins, aggregates, preloading, and query composition. Use for building flexible database queries in Elixir applications.

Use when setting up or configuring Storybook for a project. Covers main configuration, addons, builders, and framework-specific setup.

Use when nim-C interoperability including calling C from Nim, wrapping C libraries, importc/exportc pragmas, header generation, FFI patterns, and building high-performance systems code integrating Nim with existing C codebases.

Use when designing GraphQL schemas with Absinthe. Covers type definitions, interfaces, unions, enums, and schema organization patterns.

Use when creating troubleshooting guides and diagnostic procedures for operational issues. Covers problem diagnosis, root cause analysis, and systematic debugging.

Use when designing modules, APIs, and system architecture requiring independent, non-overlapping components where changes in one don't affect others.