KISS Principle (Keep It Simple, Stupid)
A design principle that states systems work best when they are kept simple rather than made complex. Simplicity should be a key goal.
Definition
KISS originated in the US Navy in 1960 and was adopted by software engineering. The principle advocates for the simplest solution that works. Complexity adds maintenance burden, increases bug probability, and makes code harder to understand. Signs of KISS violations: deeply nested logic, over-engineered abstractions, using complex patterns when simple ones suffice, and premature optimization.
Why It Matters
Simple code is easier to test, debug, and maintain. According to research, developer productivity drops exponentially with code complexity. Complex solutions often create more problems than they solve. Many famous bugs (like the Ariane 5 failure) stemmed from unnecessary complexity.
Example
Complex: using a factory pattern with multiple abstraction layers to create a single type of object. KISS: using a simple constructor or factory function when the extra abstraction provides no benefit.