Rust (Backend) PUDO Checklist

1. PLAN (Architecture & Strategy)

• Framework Selection: Choose web framework (Axum, Actix-web) based on performance vs. ecosystem needs.
• Crate Ecosystem: Plan dependencies (e.g., tokio for async runtime, serde for serialization, sqlx or sea-query for DB).
• Error Handling: Define a centralized application error type using crates like thiserror or anyhow.
• State Management: Plan how application state (DB pools, config) will be shared across thread workers.

2. UNDERSTAND (Context & Auditing)

• Borrow Checker & Lifetimes: Audit data structures to minimize clones; rely on references where safe across async boundaries.
• Async Context: Ensure types crossing .await points implement Send and Sync.
• Safety: Review unsafe blocks if any exist. Justify their existence.

3. DEVELOP (Implementation)

• Structs & Traits: Define core domain models. Use #[derive(Serialize, Deserialize)] for data transfer objects.
• Routes: Implement handlers with strongly typed extractors (Json, Path, Query).
• Database: Use compile-time checked SQL queries (e.g., sqlx::query!) for type safety.
• Testing: Write inline unit tests (#[test]) and asynchronous integration tests (#[tokio::test]).

4. OPTIMIZE (Performance & Review)

• Binary Size & Speed: Review Cargo.toml profiles (e.g., strictly opt-level = 3, LTO enabled for release).
• Memory Allocation: Profile long-lived objects. Consider Arc for shared read-only state instead of cloning.
• Compilation Time: Use cargo clippy and cargo fmt to enforce idiomatic code and avoid macro bloat where unnecessary.
• Logging: Configure structured async logging using tracing and tracing-subscriber.