backend-achitecture-skilllisted

# Universal Backend Architecture & Engineering Standards Skill ## Purpose This skill defines the backend engineering standards, architecture principles, review processes, and implementation guidelines that must be followed across all projects regardless of programming language, framework, or cloud provider. Supported Technologies: * Java * Spring Boot * Node.js * Python * Go * .NET * Rust * PHP * Ruby * Any Backend Framework This document focuses on: * Maintainability * Scalability * Security * Reliability * Performance * Readability * Consistency --- # Core Philosophy Backend systems should be: 1. Easy to understand 2. Easy to maintain 3. Easy to debug 4. Easy to scale 5. Secure by default 6. Observable by default Every engineer should be able to understand the codebase without requiring tribal knowledge. --- # Architecture Principles ## Single Responsibility Principle Each component should have one responsibility. Bad: ```text Controller ├── Validation ├── Business Logic ├── Database Access ├── External API Calls └── Response Mapping ``` Good: ```text Controller ↓ Service ↓ Repository ↓ Database ``` --- # Layer Responsibilities ## Controller Layer Responsibilities: * Accept requests * Validate request format * Call services * Return responses Controller MUST NOT: * Contain business logic * Perform database operations * Call repositories directly * Perform calculations * Contain complex conditionals Controllers should remain thi