Writing reliable shell scripts without tests leads to production failures. This skill teaches comprehensive Bats testing patterns to validate shell scripts with unit tests, fixtures, and CI/CD integration.

Write Bash scripts that fail safely and are easier to debug. This skill provides defensive patterns for errors, inputs, and cleanup.

Trading backtests often hide bias and overstate performance. This skill provides patterns and checks to design trustworthy backtests that handle look-ahead bias, survivorship bias, and transaction costs properly.

You need clear guidance for secure authentication and authorization choices. This skill provides proven patterns and examples you can adapt quickly for JWT, OAuth2, and session management.

Threat paths are hard to map and explain. This skill provides structured attack tree templates and analysis guidance for clearer risk communication and defense planning.

Build high-performance Python applications with async/await patterns. Learn concurrent programming techniques for scalable I/O-bound systems.

Building maintainable backend systems requires proven architecture patterns. This skill helps you implement Clean Architecture, Hexagonal Architecture, and Domain-Driven Design to create testable, scalable applications with proper separation of concerns.

Teams lose context when decisions are undocumented or scattered. This skill provides ADR templates, lifecycle guidance, and review checklists to capture decisions consistently.

API design decisions often become inconsistent and hard to maintain. This skill provides clear patterns, templates, and checklists to guide your choices.

Legacy AngularJS code blocks modern features and maintenance. This skill provides a clear, incremental migration path with hybrid patterns and best practices.

Airflow DAGs can fail when structure and retries are not consistent. This skill provides clear patterns for design, sensors, testing, and alerts that improve pipeline reliability.

Build inclusive digital experiences that comply with WCAG 2.2 standards. This skill provides code patterns, guidelines, and best practices for screen readers, keyboard navigation, and mobile accessibility.

WooCommerce documentation requires specific markdown formatting standards. This skill ensures your markdown files follow WooCommerce linting rules and style guidelines.

WooCommerce developers need to run tests and linting to ensure code quality. This skill provides the exact commands and workflows for PHP unit tests, JavaScript tests, and code style checks in the WooCommerce monorepo.

Inconsistent capitalization in UI text creates confusion and reduces accessibility. This skill provides clear rules for sentence case usage in WooCommerce copy, ensuring user-facing text is readable, modern, and accessible across all languages.

Ensuring code quality in WooCommerce development can be challenging with multiple coding standards. This skill automates code review by checking against WooCommerce's specific PHP, JavaScript, and UI text guidelines.

WooCommerce backend development requires following strict project conventions for classes, hooks, and testing. This skill provides comprehensive guidelines for creating standards-compliant PHP code that integrates properly with the WooCommerce architecture.

Managing Outlook contacts and calendar through a chat interface is tedious and fragmented. This skill lets Claude search contacts, schedule Teams meetings, and log notes in one workflow.

Managing calendar events and scheduling meetings with multiple attendees is time-consuming. This skill integrates Google Calendar with your contact network, enabling Claude to schedule meetings, find free time slots, and manage your calendar through natural language commands.

Professional contacts are scattered across Google, LinkedIn, Microsoft, and your phone. Rarefriend skills unify them into one searchable CRM. Your AI assistant can search, tag, add notes, schedule meetings, and import contacts on your behalf.