# Build Reliable Elixir and Phoenix Systems

Elixir projects require careful decisions about concurrency, supervision, data boundaries, testing, and performance. This skill provides focused guidance for idiomatic, fault-tolerant implementations.

## Install

```bash
npx skillstore add sickn33/elixir-pro
```

## Metadata

- Status: approved
- Slug: sickn33-elixir-pro
- Skillstore revision: r2
- Version status: missing
- Tree hash: e010116c9317e4a3e2d32f16fd918afcb5469cc5981ed59b30be26ac94272848
- Author: sickn33
- GitHub username: sickn33
- License: MIT
- Repository: https://github.com/sickn33/antigravity-awesome-skills/tree/main/skills/elixir-pro
- Ref: 88a8e9a07f4c54ab105c1c41b6267c287146b07b
- Supported tools: Claude, Codex, Claude Code
- Audit status: complete
- Agent install advisory: allowed
- Manual install advisory: allowed
- Artifact signature: available
- Audit attestation: unavailable
- Human verification: not\_verified
- Risk factors: external\_commands
- Quality score: 78
- Quality tier: bronze
- Public page: https://skillstore.pages.dev/skills/sickn33-elixir-pro
- Manifest: https://skillstore.pages.dev/api/skills/sickn33-elixir-pro/manifest

## Capabilities

- Designs OTP applications using GenServer, Supervisor, and Application patterns.
- Structures Phoenix applications with contexts and clean boundaries.
- Guides LiveView features for real-time user interfaces.
- Models database operations with Ecto changesets and explicit validation.
- Creates ExUnit testing strategies with doctests, asynchronous tests, and property-based coverage.
- Recommends Dialyzer, Benchee, Telemetry, Observer, and Recon practices.

## Use Cases

- Structure a New OTP Service: Plan process ownership, supervision boundaries, restart behavior, and test coverage for a new service.
- Improve a Phoenix Application: Review contexts, LiveView state, Ecto changesets, and application boundaries for maintainability.
- Diagnose BEAM Performance: Develop a measurement plan using Telemetry, Benchee, Observer, and Recon before changing system behavior.

## Prompt Templates

### Review an Elixir Module

```
Review this Elixir module for idiomatic pattern matching, guard clauses, clear errors, and testability. Explain each recommendation and propose focused tests.
```

### Design a Supervision Tree

```
Design an OTP supervision tree for these workers and dependencies: [details]. Define ownership, restart strategies, failure boundaries, startup order, and ExUnit tests.
```

### Plan a LiveView Feature

```
Plan this Phoenix LiveView feature: [requirements]. Separate context logic, Ecto validation, LiveView state, events, authorization checks, telemetry, and integration tests.
```

### Investigate a Distributed Bottleneck

```
Analyze these symptoms and measurements from a clustered Elixir system: [evidence]. Form hypotheses, rank risks, and design Observer, Recon, Telemetry, and Benchee experiments.
```

## Limitations

- It does not execute, compile, profile, or deploy an Elixir project by itself.
- Recommendations require validation against the project version, dependencies, infrastructure, and production workload.
- The packaged skill does not include the referenced implementation playbook.
- It does not replace security review, database planning, or distributed systems testing.

## Best Practices

- Provide Elixir, Erlang, Phoenix, Ecto, and dependency versions with each request.
- Describe process ownership, expected failures, workload, and recovery requirements before selecting OTP patterns.
- Validate recommendations with ExUnit, Dialyzer, benchmarks, telemetry, and representative production conditions.

## Anti Patterns

- Do not add processes when a pure function or existing process already provides clear ownership.
- Do not choose supervision strategies without defining expected failures and restart dependencies.
- Do not optimize BEAM behavior before collecting representative measurements.

## Security Audit

- Audited at: 2026-07-23T23:17:13.724\+00:00
- Summary: The sole static finding is a false positive caused by Markdown backticks around a referenced file path. No command execution or malicious intent appears in SKILL.md.

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