Pair Programming: 1. You need to solve programming exercise with TDD approach. If you don't have experience with TDD, they still force you to follow same approach to solve exercise. 2. If you don't follow TDD, You will gets rejected. 3. If candidate ask for reasons for rejection they won't give satisfactory reason. If you didn't worked on TDD before, then they don't even evaluate on technical skills. They must mention first level scrutiny of candidates having hands on experience in TDD.