Benefits (of using TDD to solve this problem) Detect special cases by using this method Simpler code with TDD than without using TDD See the patterns and after a while, reduce the patterns to something simpler Maybe a too simple problem, but we practice and latter if we found a more elaborate one, we will the same method and have a great benefit at the end. in this session, I understand how to write tests first time some of the people of the session write tests Costs We need more preparation: find new problems to solve, prepare the environment for coding with your favorite language, ... long time to solve the problem (for a very simple problem)