Theory of testing is usually differs from practice. Today we want to talk about our practical experience in testing application's code which is used by millions of iOS users and about the difficult path that our team finished in order to achieve stable code.

Let’s imagine: the developers successfully convinced themselves and the business of the need to cover the code with tests. Over time, in the project were created more than a dozen thousand unit- and more than a thousand UI-tests. Such a large test base araised several problems, and we successfully found the solution for them.