Research a codebase and create architectural documentation describing how features or systems work. Use when the user asks to: (1) Document how a feature works, (2) Create an architecture overview, (3) Explain code structure for onboarding or knowledge transfer, (4) Research and describe a system's design. Produces markdown documents with Mermaid diagrams and stable code references suitable for humans and AI agents.

Create a release checklist and GitHub issue for an R package. Use when the user asks to "create a release checklist" or "start a release" for an R package.

Best practices for writing R package tests using testthat version 3+. Use when writing, organizing, or improving tests for R packages. Covers test structure, expectations, fixtures, snapshots, mocking, and modern testthat 3 patterns including self-sufficient tests, proper cleanup with withr, and snapshot testing.

Prepare R packages for CRAN submission by checking for common ad-hoc requirements not caught by devtools::check(). Use when: (1) Preparing a package for first CRAN release, (2) Preparing a package update for CRAN resubmission, (3) Reviewing a package to ensure CRAN compliance, (4) Responding to CRAN reviewer feedback. Covers documentation requirements, DESCRIPTION field standards, URL validation, examples, and administrative requirements.

Conduct rigorous, adversarial code reviews with zero tolerance for mediocrity. Use when users ask to "critically review" my code or a PR, "critique my code", "find issues in my code", or "what's wrong with this code". Identifies security holes, lazy patterns, edge case failures, and bad practices across Python, R, JavaScript/TypeScript, SQL, and front-end code. Scrutinizes error handling, type safety, performance, accessibility, and code quality. Provides structured feedback with severity tiers (Blocking, Required, Suggestions) and specific, actionable recommendations.

**Skill Name:**

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Provides AWS Secrets Manager patterns using AWS SDK for Java 2.x. Use when storing/retrieving secrets (passwords, API keys, tokens), rotating secrets automatically, managing database credentials, or integrating secret management into Spring Boot applications.

Provides core patterns and best practices for AWS SDK for Java 2.x. Use when configuring AWS service clients, setting up authentication, managing credentials, configuring timeouts, HTTP clients, or following AWS SDK best practices.

Provides tool and function calling patterns with LangChain4j. Handles defining tools, function calls, and LLM agent integration. Use when building agentic applications that interact with tools.

Provides AWS RDS (Relational Database Service) management patterns using AWS SDK for Java 2.x. Use when creating, modifying, monitoring, or managing Amazon RDS database instances, snapshots, parameter groups, and configurations.

Provides patterns for unit testing @ConfigurationProperties classes with @ConfigurationPropertiesTest. Use when validating application configuration binding and validation.

Provides optimal chunking strategies in RAG systems and document processing pipelines. Use when building retrieval-augmented generation systems, vector databases, or processing large documents that require breaking into semantically meaningful segments for embeddings and search.

Generates comprehensive TypeScript documentation using JSDoc, TypeDoc, and multi-layered documentation patterns for different audiences. Use when creating API documentation, architectural decision records (ADRs), code examples, and framework-specific patterns for NestJS, Express, React, Angular, and Vue.

Provides repeatable CRUD workflows for Spring Boot 3 services with Spring Data JPA and feature-focused architecture. Use when modeling aggregates, repositories, controllers, and DTOs for REST APIs.

Provides AWS CloudFormation patterns for Lambda functions, layers, event sources, and integrations. Use when creating Lambda functions with CloudFormation, configuring API Gateway, Step Functions, EventBridge, SQS, SNS triggers, and implementing template structure with Parameters, Outputs, Mappings, Conditions, cross-stack references, and best practices for cold start optimization.

Provides Event-Driven Architecture (EDA) patterns in Spring Boot using ApplicationEvent, @EventListener, and Kafka. Use when building loosely-coupled microservices with domain events, transactional event listeners, and distributed messaging patterns.

Provides AWS CloudFormation patterns for infrastructure security, secrets management, encryption, and secure data handling. Use when creating secure CloudFormation templates with AWS Secrets Manager, KMS encryption, secure parameters, IAM policies, VPC security groups, TLS/SSL certificates, and encrypted traffic configurations. Covers template structure, parameter best practices, cross-stack references, and defense-in-depth strategies.

Provides Model Context Protocol (MCP) server implementation patterns with Spring AI. Use when building MCP servers to extend AI capabilities with custom tools, resources, and prompt templates using Spring's official AI framework.

Provides AWS CloudFormation patterns for Amazon RDS databases. Use when creating RDS instances (MySQL, PostgreSQL, Aurora), DB clusters, multi-AZ deployments, parameter groups, subnet groups, and implementing template structure with Parameters, Outputs, Mappings, Conditions, and cross-stack references.