Practice TDD with the FizzBuzz kata. Follow Red-Green-Refactor: (1) Write failing test for input 1 → "1", (2) Make it pass (simplest code), (3) Refactor, (4) Repeat for: multiples of 3 → "Fizz", multiples of 5 → "Buzz", multiples of both → "FizzBuzz". Document each cycle. Final code should be clean. Reflect: how did TDD change your design?
