If your writing tests after the unit then you not doing TDD right. TDD is not designed to be a good technique for developing algorithm's but rather for designi

If your writing tests after the unit then you not doing TDD right. TDD is not designed to be a good technique for developing algorithm's but rather for designing OO systems and discovering the collaborations between various objects within a system. This doesn't mean you can forget about solid OO design principals and just somehow land up with a good design just because you use TDD.