claude-essentials

Writing style and tone guide for human-sounding content. Use when writing documentation, READMEs, commit messages, PR descriptions, blog posts, LinkedIn posts, social media content, or any user-facing content.

Executes implementation plans with smart task grouping. Groups related tasks to share context, parallelizes across independent subsystems.

Diagnose and fix tests that pass in isolation but fail when run concurrently. Covers shared state isolation, resource conflicts, and timing-based flakiness.

Guides CI/CD pipeline architecture, security hardening, and deployment strategies for GitHub Actions. Use when designing workflows, securing supply chains, optimizing build performance, configuring deployments, managing infrastructure as code pipelines, or setting up pipeline observability.

Defines product features from a PM perspective before technical planning begins. Use when scoping new features, writing product specs, defining user problems, choosing what to build, researching existing patterns, or bridging the gap between strategy and implementation. Covers JTBD analysis, competitive research, UX/DX experience definition, and scope negotiation for consumer, B2B, and developer tool products.

Writes behavior-focused tests using Testing Trophy model with real dependencies. Use when writing tests, choosing test types, or avoiding anti-patterns like testing mocks.

Guides clean, scalable system architecture during the build phase. Use when designing modules, defining boundaries, structuring projects, managing dependencies, or preventing tight coupling and brittleness as systems grow.

Review a completed session to extract actionable improvements. Identifies DX friction, documentation gaps, architectural confusion, anti-patterns, process failures, and skill/config improvements. Uses progressive disclosure for targeted investigation types.

Debugging framework that finds root causes before proposing fixes. Use when investigating bugs, errors, unexpected behavior, failed tests, or when previous fixes haven't worked.

Selects and applies professional journalistic story structures (WSJ Formula, Inverted Pyramid, Hourglass, Tick-Tock, etc.) based on the content being written. Use when writing articles, blog posts, features, essays, long-form content, news stories, trend pieces, investigative reports, profiles, or any narrative prose longer than a few paragraphs. Also use when the user asks for help structuring a piece, choosing a story framework, organizing a draft, outlining an article, or wants to know which article format fits their content. Trigger on requests like "help me structure this," "what format should I use," "write a feature about," "draft a blog post on," or any mention of story structure, article architecture, or narrative frameworks. Complements the writer skill (which handles tone and anti-AI rhetoric) by providing the structural blueprint.

Enforces precise, minimal design for dashboards and admin interfaces. Use when building SaaS UIs, data-heavy interfaces, or any product needing Jony Ive-level craft.

Prevents silent failures and context loss in error handling. Use when writing try-catch blocks, designing error propagation, reviewing catch blocks, or implementing Result patterns.

Guides database architecture decisions for PostgreSQL, DuckDB, Parquet, PGVector, and Neo4j. Use when designing schemas, choosing storage strategies, optimizing queries, tuning maintenance, configuring vector search, modeling graph data, or diagnosing performance issues across OLTP, OLAP, similarity search, and graph workloads.

Measure-first performance optimization that balances gains against complexity. Use when addressing slow code, profiling issues, or evaluating optimization trade-offs.

Analyzes logs efficiently through targeted search and iterative refinement. Use when investigating errors, debugging incidents, or analyzing patterns in application logs.

Produces executive-quality strategic documents in The Economist/HBR style. Use when writing strategy memos, market analysis, business cases, customer research reports, or any document for Product, Design, and Business leaders. Customer-led, evidence-based, narrative-driven.

Trains Claude to write SQL at Staff+ DBA level by targeting the non-obvious patterns Claude's defaults miss. Covers multi-column statistics for correlated predicates, operator class selection for index usage, aggregate FILTER patterns, keyset pagination, and the query anti-patterns that silently destroy production performance. Use when writing complex SQL, reviewing a query for correctness or performance, adding indexes, or optimizing a slow query.

Creates professional Mermaid diagrams with semantic styling and visual hierarchy. Use when creating flowcharts, sequence diagrams, state machines, class diagrams, or architecture visualizations.