Donna Bogatin writes that Google has lowest ratio of testers to developers. They can work like this because their self-testing and code reviewing ability reduces the burden on testers. However, I think there are two aspects we are looking at here. The testing that is done is usually to find out if the implementation functions as per intended in the design or whether the software satisfies the user’s requirements or not. However, there are lot of intermediate atomic tests required like unit tests which can be carried out by the developers themselves, thanks to some fantastic tools. These unit tests and code reviews can help identify certain bugs much earlier, that is, in the developer ring, before reaching the testers. This can reduce the cycle time drastically and elevate the efficiency. However, this does not mean that the tests for design compliance or requirements satisfaction can be omitted. Google can hire lesser testers because their developers play the role of testers for intermediate tests, and I think it should work for quite a lot of us.