code-quality-principles

name	code-quality-principles
description	Applies KISS, YAGNI, and SOLID principles for clean code with reduced complexity. Use when refactoring or reviewing code for over-engineering.
alwaysApply	true
category	development
tags	["design","principles","clean-code","architecture"]
tools	[]
complexity	low
model_hint	fast
estimated_tokens	600

Code Quality Principles

Guidance on KISS, YAGNI, and SOLID principles with language-specific examples.

When To Use

• Improving code readability and maintainability
• Applying SOLID, KISS, YAGNI principles during refactoring

When NOT To Use

• Throwaway scripts or one-time data migrations
• Performance-critical code where readability trades are justified

KISS (Keep It Simple, Stupid)

Principle: Avoid unnecessary complexity. Prefer obvious solutions over clever ones.

Guidelines

Prefer	Avoid
Simple conditionals	Complex regex for simple checks
Explicit code	Magic numbers/strings
Standard patterns	Clever shortcuts
Direct solutions	Over-abstracted layers

Python Example

# Bad: Overly clever one-liner
users = [u for u in (db.get(id) for id in ids) if u and u.active and not u.banned]

# Good: Clear and readable
users = []
for user_id in ids:
    user = db.get(user_id)
    if user and user.active and not user.banned:
        users.append(user)

Rust Example

// Bad: Unnecessary complexity
fn process(data: &[u8]) -> Result<Vec<u8>, Box<dyn std::error::Error>> {
    data.()
        .(|&b| b.().())
        .collect::<<<_>, _>>()
        .(|e| e.())
}


 (data: &[])  <<>, & > {
      = ::(data.());
     &byte  data {
        result.(byte.().()?);
    }
    (result)
}