arnesto

Design robust A/B test experiments. Use when testing a new feature, validating a hypothesis, or optimizing conversion rates.

**STOP AND VERIFY**: Before running any command or tool that results in irreversible data loss, you MUST obtain explicit user consent. When in doubt, ask. It is better to wait for confirmation than to accidentally delete production data or critical project assets. Use this for: - SQL: DROP TABLE/VIEW/SCHEMA/DATABASE, TRUNCATE, or broad DELETE (missing WHERE or using 1=1). - Cloud Storage: gsutil rm or gcloud storage rm targeting production data or critical buckets. - Infrastructure: gcloud projects delete, deleting Spanner/BigQuery/Dataproc resources, deleting secrets, or KMS key destruction.

Audit, update, and publish cross-tool agent configuration through Arnesto. Use for agent configuration instructions, AGENTS.md hierarchies, always-loaded rules, skill routing, client wrappers, local runtime boundaries, or instruction/context cleanup.

Guide realistic AI-assisted coding interview rehearsals, timed mocks, and evidence-based scoring. Use for live backend AI coding interview practice that needs interviewer, coach, and coding-agent roles; do not use for ordinary feature implementation.

Reference patterns for augmented coding with AI. Use when discussing AI coding patterns, anti-patterns, obstacles, context management, steering AI, or looking up Lexler's patterns collection.

Presents a proposed approach in progressive confirmable chunks with recommended decisions and alternatives. Use when aligning on a design, plan, or technical approach before implementation.

Writes approval tests (snapshot/golden master testing) for Python, JavaScript/TypeScript, or Java. Use when verifying complex output, characterization testing legacy code, testing combinations, or working with .approved/.received files.

Use this skill to create Cursor Automations.

Keep a PR merge-ready by triaging comments, resolving clear conflicts, and fixing CI in a loop.

Use on demand when the user asks to remove AI-isms, audit AI-sounding prose, or clean up a named draft while preserving meaning and structure. Includes a Spanish/English communication profile. Recommend Humanizer for a broader author-voice rewrite; a recommendation does not activate either skill.

Scannable BDD tests written in domain language. Use when doing BDD.

Discovers and inspects BigQuery Data Transfer Service (DTS) configurations. Use this to identify existing ingestion pipelines and extract datasource or transfer config metadata for data pipelines. Use when a user asks for ingestion scenarios while building or managing data pipelines or when a user asks to "ingest" or "add" data that may already be managed by a DTS transfer.

Build modern data apps, dashboards, and interactive reports using either React + Vite or Streamlit. Includes optional Gemini Data Analytics chat integration for an AI powered "chat with your data" experience. Relevant when any of the following conditions are true: 1. User explicitly requests to build a data dashboard, data application, or visualization UI, and the UI pulls data from a GCP database (defaulting to BigQuery unless otherwise specified). 2. You need to generate a frontend web application to interact with, query, and visualize data from GCP data sources. 3. User wants to build a "chat with your data" experience or integrate the Gemini Data Analytics chat API into a web interface. Do NOT use when any of the following conditions are true: 1. The request is for building backend-only services. 2. The request is for simple CLI scripts or command-line applications. 3. The web application is not data-centric or does not involve visualizing/querying data from GCP sources.

JS/TS/JSX toolkit with Bun awareness. Use when using Bun as a runtime, test runner, or package manager in JavaScript and TypeScript projects.

A Cursor Canvas is a live React app that the user can open beside the chat. You MUST use a canvas when the agent produces a standalone analytical artifact — quantitative analyses, billing investigations, security audits, architecture reviews, data-heavy content, timelines, charts, tables, interactive explorations, repeatable tools, or any response that benefits from visual layout. Especially prefer a canvas when presenting results from MCP tools (observability, analytics, issue-tracking and messaging tools) where the data is the deliverable — render it in a rich canvas rather than dumping it into a markdown table or code block. If you catch yourself about to write a markdown table, stop and use a canvas instead. You MUST also read this skill whenever you create, edit, or debug any .canvas.tsx file.

Ultra-compressed communication mode. Cuts token usage ~75% by dropping filler, articles, and pleasantries while keeping full technical accuracy. Use when user says "caveman mode", "talk like caveman", "use caveman", "less tokens", "be brief", or invokes /caveman.

Ingest Claude Code conversation history into the Obsidian wiki. Use this skill when the user wants to mine their past Claude conversations for knowledge, import their ~/.claude folder, extract insights from previous coding sessions, or says things like "process my Claude history", "add my conversations to the wiki", "what have I discussed with Claude before". Also triggers when the user mentions their .claude folder, Claude projects, session data, past conversation logs, local-agent-mode sessions, or audit logs.

Use the local CodeGraph CLI or an already configured MCP server to find symbols, callers, dependencies, and change impact in a repository. Use when the user names CodeGraph or repeated structural code exploration would benefit from a reusable index. Not for a simple text lookup, prose-only repositories, or automatic installation into every agent.

Use when a task should trigger a local completion notification through code-notify, or when configuring cross-tool notification behavior for Codex, Cursor, Claude, Gemini, or similar agent workflows. Verify the installed command or existing local integration before relying on it.

Simplifies and refines code for clarity, readability, and maintainability. Reduces complexity without changing behavior. Use when simplifying, cleaning up, or reducing complexity in code.