Skill UI

This skill provides expert guidance for building robust, scalable, and fault-tolerant applications using Elixir. It specializes in mastering OTP patterns, Phoenix LiveView, concurrent programming, and distributed system design. Use it for complex Elixir development tasks requiring best practices and high reliability.

Phoenix is an open-source observability platform for tracing, evaluating, and monitoring LLM applications; use it to debug prompts, run dataset evaluations, build experiment pipelines, and watch production inference in real time.

The Phoenix CLI is a powerful tool for debugging complex LLM and agent workflows. It allows users to fetch detailed traces, spans, and sessions, analyze errors, and structure findings using open and axial coding techniques. It is essential for investigating complex LLM failures, building robust failure taxonomies, and guiding the next steps in application evaluation after initial instrumentation.

Phoenix Evals enables developers to build and run evaluators for AI and LLM applications. It supports both code-based and LLM-based evaluation methods, including RAG systems. Users can create datasets, run experiments, validate evaluator accuracy, and implement production guardrails. Available in Python and TypeScript, it helps ensure model performance and reliability through systematic testing and human validation.

Instrument LLM applications with OpenInference semantic conventions in Phoenix. Covers setup, auto and manual instrumentation, 9 span types, session tracking, production batching and PII masking for Python and TypeScript.

Write idiomatic Elixir code with OTP patterns, supervision trees, Ecto, and Phoenix LiveView. Covers concurrency, fault tolerance, distributed systems, and BEAM performance optimization.