Rust Expert

Use when building a REST/HTTP backend in Rust — axum routing, extractors, shared state, middleware, error responses, sqlx database access. Not for raw async/concurrency (rust-async-concurrency).

Use when structuring a Cargo workspace or building a Rust CI pipeline — fmt, clippy, cargo-deny/audit, nextest, coverage, MSRV. Not for writing the tests themselves (rust-testing-quality).

Use when writing or reviewing idiomatic Rust — edition 2024 ownership/borrowing design, or fixing LLM pitfalls (clone tax, unwrap infestation, indexed loops). Not for error-type design (rust-error-handling) or SOLID layout (solid-rust).

Use when designing Rust error handling — thiserror vs anyhow, typed error enums,

Use when writing, organizing, or running Rust tests — unit, integration, doc-tests, proptest, criterion benchmarks, or cargo-mutants. Not for CI pipeline wiring (rust-tooling-cicd).

Use when choosing crates for a Rust project — serialization, CLI, async runtime, web, database, HTTP client, error handling, observability. Not for API usage details of an already-chosen crate.

Use when writing async Rust — spawning tasks, sharing state across tasks/threads, choosing channels vs mutexes, or hitting Send-bound errors with async traits. Not for HTTP service structure (rust-web-backend) or sync-only ownership (rust-core-language).