KISS, YAGNI & the Cost-of-Change Curve

Software is easiest to manage when it stays simple. Three popular principles—KISS (Keep It Simple, Stupid), YAGNI (You Aren’t Gonna Need It), and the Cost-of-Change Curve—remind you not to build unnecessary features or overcomplicate solutions.

The simpler your code, the easier it is to understand, maintain, and change later. Adding too many features early can make everything harder and slower in the long run.

Real-Life Analogy: Packing for a Trip

When going on holiday, it’s tempting to pack for every possible situation. But a lighter bag is easier to carry, and you can buy extra things if truly needed. The same applies to writing code: build only what you need, and add more later if required.

• KISS: Simpler code is faster and easier to manage.
• YAGNI: Don't add features until you really need them.
• Cost-of-Change: Making changes is cheapest early, harder later.

Benefits of Simplicity

Simple code takes less time to write, test, and fix. Over-complicated solutions slow you down and make future changes harder.

• Less code means fewer bugs.
• New features are easier to add.

When to Add Features

Don’t build for imaginary needs. Focus on the real requirements—add extra features only if they become necessary.

• Prioritise current needs, not possible futures.
• It’s easier to add later than remove unnecessary code.

Final Thoughts

Start simple, avoid guessing the future, and keep your project light and easy to change. Simplicity wins every time.