Elixir Performance Review

Reviews Elixir code for performance issues including GenServer bottlenecks, memory usage, and concurrency patterns. Use when reviewing high-throughput code o...

Security Scan

This is an instruction-only Elixir performance review checklist and reference pack that is internally consistent with its stated purpose and requests no credentials or installs.

Purpose & Capability

Name and description match the contents: the skill is a code-review checklist and reference material for Elixir performance patterns. It requires no binaries, env vars, or external services, which is proportionate for a guidance-only skill.

Instruction Scope

SKILL.md and the included reference files confine guidance to reviewing Elixir code (GenServer, ETS, memory, concurrency). The only minor inconsistency: SKILL.md instructs the agent to "Load and follow [review-verification-protocol](../review-verification-protocol/SKILL.md)" before reporting issues, but that referenced file is not included in the manifest. This may be a broken/relative link (documentation bug) but not an obvious security concern.

Install Mechanism

No install spec or code files — instruction-only. Nothing is written to disk or downloaded by the skill itself.

Credentials

The skill declares no required environment variables, credentials, or config paths. The guidance does not attempt to read or require unrelated secrets.

Persistence & Privilege

always:false and default autonomous invocation are used (normal). The skill does not request persistent privileges or modify other skills or system-wide settings.

Assessment

This skill is a documentation-only review checklist for Elixir performance and appears coherent and low-risk. Note the SKILL.md refers to a verification protocol file that isn't included — that is likely a documentation bug rather than malicious behavior. Before using the skill with real code, avoid pasting sensitive secrets or credentials into the agent prompts (the skill does not need them). If you rely on the missing review-verification-protocol, ask the publisher for the file or inspect whatever verification steps they expect before reporting issues.

Quick Reference

Issue Type	Reference
Mailbox overflow, blocking calls	references/genserver-bottlenecks.md
When to use ETS, read/write concurrency	references/ets-patterns.md
Binary handling, large messages	references/memory.md
Task patterns, flow control	references/concurrency.md

Review Checklist

GenServer

• Not a single-process bottleneck for all requests
• No blocking operations in handle_call/cast
• Proper timeout configuration
• Consider ETS for read-heavy state

Memory

• Large binaries not copied between processes
• Streams used for large data transformations
• No unbounded data accumulation

Concurrency

• Task.Supervisor for dynamic tasks (not raw Task.async)
• No unbounded process spawning
• Proper backpressure for message producers

Database

• Preloading to avoid N+1 queries
• Pagination for large result sets
• Indexes for frequent queries

Valid Patterns (Do NOT Flag)

• Single GenServer for low-throughput - Not all state needs horizontal scaling
• Synchronous calls for critical paths - Consistency may require it
• In-memory state without ETS - ETS has overhead for small state
• Enum over Stream for small collections - Stream overhead not worth it

Context-Sensitive Rules

Issue	Flag ONLY IF
GenServer bottleneck	Handles > 1000 req/sec OR blocking I/O in callbacks
Use streams	Processing > 10k items OR reading large files
Use ETS	Read:write ratio > 10:1 AND concurrent access

Before Submitting Findings

Load and follow review-verification-protocol before reporting any issue.