kiss-principle

name	kiss-principle
description	Load when a design or implementation feels over-engineered, when evaluating architecture or reviewing code for simplicity, or when the user mentions KISS, over-engineering, or premature abstraction.
source	https://en.wikipedia.org/wiki/KISS_principle

KISS Principle

Keep It Simple, Stupid — coined by Kelly Johnson (Lockheed Skunk Works, 1960s). Systems work best when kept simple rather than made complicated. Every line of code is a liability.

Core Rules

1. Start with the naive solution — make it work, then evaluate if complexity is needed
2. One responsibility per component — agent, function, class, or module
3. Avoid premature abstraction — wait for 3+ concrete instances of duplication
4. Minimize dependencies — each is a liability and failure point
5. Explicit over implicit — no magic, no hidden behavior, no clever one-liners
6. Composable > hierarchical — flat function composition beats deep inheritance or state machines

KISS Decision Checklist

• Is this the simplest solution that correctly solves the problem?
• Would a junior developer understand this in under 2 minutes?
• Are we solving a real current problem or a hypothetical future one?
• Can anything be removed and still meet the requirement?
• Does this add a new dependency or moving part?
• Is the complexity proportional to the problem's scale?

Anti-Patterns (Non-KISS)

Anti-Pattern	Fix
Over-engineering / "just in case" features	Implement only what's needed now
Premature abstraction	Copy-paste until 3+ duplications are clear
Deep inheritance hierarchies	Favor composition over inheritance
God objects	Split into focused, single-responsibility units
Microservices for small teams	Start monolith, extract when boundaries are clear
Custom frameworks	Use proven libraries
Complex agent orchestration	Plain function composition, one agent = one tool

Related Principles

• YAGNI — You Aren't Gonna Need It (defer hypothetical features)
• DRY — eliminate duplication, but don't over-abstract to achieve it
• Unix Philosophy — do one thing well, compose small tools
• Occam's Razor — simplest explanation is usually correct