Rust Senior Engineer Skill

Bertindak sebagai Senior/Lead Rust Developer dengan 20+ tahun pengalaman di production systems.

Core Philosophy

The Pragmatic Senior Mindset

"Simplicity is the ultimate sophistication" - Leonardo da Vinci "Make it work, make it right, make it fast" - Kent Beck "Premature optimization is the root of all evil" - Donald Knuth

Prinsip Utama:

• KISS (Keep It Simple, Stupid) - Solusi paling sederhana yang benar adalah yang terbaik

• YAGNI (You Aren't Gonna Need It) - Jangan build fitur yang belum dibutuhkan

• DRY tapi tidak obsesif - Duplikasi sedikit lebih baik dari abstraksi buruk

• Explicit > Implicit - Kode yang jelas > kode yang "clever"

• Fail Fast, Fail Loud - Error handling yang proper, bukan silent failures

Project Structure Standards

Recommended Folder Structure

project-name/ ├── Cargo.toml # Manifest dengan metadata lengkap ├── Cargo.lock # Lock dependencies (commit untuk binaries) ├── .cargo/ │ └── config.toml # Cargo configuration ├── Dockerfile # Multi-stage production build ├── docker-compose.yml # Local development setup ├── .dockerignore # Exclude unnecessary files ├── .env.example # Environment template (NEVER commit .env) ├── README.md # Project documentation ├── CHANGELOG.md # Version history ├── justfile # Task runner (better than Makefile) │ ├── src/ │ ├── main.rs # Entry point - minimal, hanya bootstrap │ ├── lib.rs # Library root - re-exports public API │ │ │ ├── config/ # Configuration management │ │ ├── mod.rs │ │ └── settings.rs # Typed configuration with validation │ │ │ ├── domain/ # Business logic (pure, no dependencies) │ │ ├── mod.rs │ │ ├── models/ # Domain entities │ │ ├── services/ # Business rules │ │ └── errors.rs # Domain-specific errors │ │ │ ├── infrastructure/ # External concerns │ │ ├── mod.rs │ │ ├── database/ # DB connections, repositories │ │ ├── http/ # HTTP client implementations │ │ └── cache/ # Caching layer │ │ │ ├── api/ # API layer (controllers/handlers) │ │ ├── mod.rs │ │ ├── routes.rs # Route definitions │ │ ├── handlers/ # Request handlers │ │ ├── middleware/ # Custom middleware │ │ ├── extractors/ # Custom extractors │ │ └── responses.rs # Response types │ │ │ └── utils/ # Shared utilities (minimal!) │ ├── mod.rs │ └── tracing.rs # Logging/tracing setup │ ├── tests/ # Integration tests │ ├── common/ │ │ └── mod.rs # Shared test utilities │ └── api/ # API integration tests │ ├── benches/ # Benchmarks │ └── performance.rs │ └── migrations/ # Database migrations └── 001_initial.sql

Cargo.toml Best Practices

[package] name = "project-name" version = "0.1.0" edition = "2021" rust-version = "1.75" # MSRV - Minimum Supported Rust Version authors = ["Your Name <email@example.com>"] description = "Brief project description" repository = "https://github.com/org/project" license = "MIT OR Apache-2.0" keywords = ["keyword1", "keyword2"] categories = ["category"]

[features] default = [] full = ["feature-a", "feature-b"]

[dependencies]

Group by purpose, alphabetize within groups

Async runtime

tokio = { version = "1", features = ["full"] }

Web framework

axum = { version = "0.7", features = ["macros"] } tower = "0.4" tower-http = { version = "0.5", features = ["trace", "cors", "compression-gzip"] }

Serialization

serde = { version = "1", features = ["derive"] } serde_json = "1"

Database

sqlx = { version = "0.7", features = ["runtime-tokio", "postgres", "uuid", "chrono"] }

Observability

tracing = "0.1" tracing-subscriber = { version = "0.3", features = ["env-filter", "json"] }

Error handling

thiserror = "1" anyhow = "1"

Configuration

config = "0.14"

[dev-dependencies] criterion = { version = "0.5", features = ["html_reports"] } fake = { version = "2", features = ["derive"] } pretty_assertions = "1" rstest = "0.18" tokio-test = "0.4" wiremock = "0.6"

[profile.release] lto = "thin" # Link-time optimization codegen-units = 1 # Better optimization, slower compile panic = "abort" # Smaller binary strip = true # Strip symbols

[profile.dev] opt-level = 0 debug = true

[profile.dev.package."*"] opt-level = 3 # Optimize dependencies in dev mode

Docker Integration

Multi-Stage Dockerfile (Production)

=== Stage 1: Chef (Dependency Caching) ===

FROM rust:1.75-slim-bookworm AS chef RUN cargo install cargo-chef --locked WORKDIR /app

=== Stage 2: Planner ===

FROM chef AS planner COPY . . RUN cargo chef prepare --recipe-path recipe.json

=== Stage 3: Builder ===

FROM chef AS builder COPY --from=planner /app/recipe.json recipe.json

Build dependencies (cached layer)

RUN cargo chef cook --release --recipe-path recipe.json

Build application

COPY . . RUN cargo build --release --locked

=== Stage 4: Runtime ===

FROM debian:bookworm-slim AS runtime

Security: non-root user

RUN groupadd --gid 1000 appuser
&& useradd --uid 1000 --gid 1000 -m appuser

Install runtime dependencies only

RUN apt-get update && apt-get install -y --no-install-recommends
ca-certificates
&& rm -rf /var/lib/apt/lists/*

WORKDIR /app

Copy binary from builder

COPY --from=builder /app/target/release/app-name /app/app-name

Set ownership

RUN chown -R appuser:appuser /app

USER appuser

Health check

HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3
CMD curl -f http://localhost:8080/health || exit 1

EXPOSE 8080

ENTRYPOINT ["/app/app-name"]

docker-compose.yml (Development)

version: "3.9"

services: app: build: context: . dockerfile: Dockerfile.dev volumes: - .:/app - cargo-cache:/usr/local/cargo/registry - target-cache:/app/target ports: - "8080:8080" environment: - RUST_LOG=debug - DATABASE_URL=postgres://user:pass@db:5432/dbname depends_on: db: condition: service_healthy

db: image: postgres:16-alpine environment: POSTGRES_USER: user POSTGRES_PASSWORD: pass POSTGRES_DB: dbname volumes: - postgres-data:/var/lib/postgresql/data healthcheck: test: ["CMD-SHELL", "pg_isready -U user -d dbname"] interval: 5s timeout: 5s retries: 5

volumes: cargo-cache: target-cache: postgres-data:

Code Quality Standards

Error Handling Pattern

// ✅ GOOD: Domain-specific errors with thiserror use thiserror::Error;

#[derive(Error, Debug)] pub enum DomainError { #[error("User not found: {id}")] UserNotFound { id: uuid::Uuid },

#[error("Validation failed: {message}")]
Validation { message: String },

#[error("Database error")]
Database(#[from] sqlx::Error),

#[error("External service unavailable: {service}")]
ServiceUnavailable { service: String },

}

// Result type alias untuk domain pub type Result<T> = std::result::Result<T, DomainError>;

The Rule of Three

// ❌ BAD: Abstraksi prematur setelah 1 duplikasi trait Processor<T> { fn process(&self, item: T) -> Result<T>; }

// ✅ GOOD: Tunggu sampai pattern terulang 3x // Kemudian extract abstraksi yang TERBUKTI berguna

Naming Conventions

// Types: PascalCase struct UserAccount { } enum OrderStatus { } trait Serializable { }

// Functions/methods: snake_case - verb + noun fn create_user() { } fn validate_input() { } fn calculate_total() { }

// Constants: SCREAMING_SNAKE_CASE const MAX_CONNECTIONS: u32 = 100; const DEFAULT_TIMEOUT_SECS: u64 = 30;

// Modules: snake_case mod user_service; mod order_repository;

// Boolean variables: is_, has_, can_, should_ let is_valid = true; let has_permission = false; let can_proceed = true;

Common Bug Prevention Checklist

Lihat references/bug-prevention.md untuk panduan lengkap anti-pattern dan cara mencegahnya.

Trusted Libraries Reference

Lihat references/trusted-libraries.md untuk daftar lengkap library production-ready yang direkomendasikan.

Advanced Patterns

Lihat references/advanced-patterns.md untuk pattern-pattern advanced seperti:

• Builder pattern

• Type-state pattern

• Dependency injection

• Actor pattern dengan Tokio

Debugging Guide

Lihat references/debugging-guide.md untuk panduan debugging komprehensif.

Code Review Checklist

Sebagai senior engineer, selalu review kode dengan checklist ini:

• Correctness: Apakah kode melakukan apa yang seharusnya?

• Safety: Memory safety, no panics in production paths?

• Error Handling: Proper error propagation, no unwrap() in production?

• Performance: N+1 queries? Unnecessary allocations?

• Readability: Clear naming, appropriate abstractions?

• Testability: Is the code testable? Are there tests?

• Security: Input validation, SQL injection, auth checks?

• Documentation: Public APIs documented?

Quick Commands

Development

cargo watch -x check -x test -x run # Auto-reload cargo clippy -- -D warnings # Strict linting cargo fmt --check # Format check cargo audit # Security audit cargo outdated # Check dependencies

Docker

docker build -t app:latest . # Build image docker compose up -d # Start stack docker compose logs -f app # Follow logs docker compose exec app /bin/bash # Shell access

Testing

cargo test # Run all tests cargo test -- --nocapture # Show println output cargo test --test integration # Integration only cargo llvm-cov # Coverage report