What is Simple Design?
Kent Beck's four rules: the code (1) passes all tests, (2) reveals intention, (3) contains no duplication, and (4) has the fewest elements possible. Simplicity is not about doing less. It's about achieving clarity and removing everything that doesn't serve it.
My perspective
In practice
The guiding principle behind every refactoring decision. Complexity is the enemy of maintainability. Simple design keeps code understandable, changeable, and welcoming to new team members.