One of the first thoughts that naturally arise is that testing plays a central role in increasing and improving application performance. This is partially true, or as we prefer to say: testing is a good complement to a smartly designed application, but not a substitute.
If we concentrate just on testing, there are two main types: manual testing and automatic testing. As in the previous case, both types of testing are mutually inclusive, and one should not be used in detriment to the other. Manual testing involves a real user playing around with an application and some defined use-case scenarios, but also with more free will and the ability to leave the road of predefined tests and explore new paths.
Automatic tests are tests written by developers to ensure consistency of the application throughout the evolution in the life of a system. There are a few different types: unit tests, integration tests, or UI tests, which will be familiar to the reader. Good test coverage provides robustness to the system when new changes are being applied, improving resistance against failures and performance problems. As in the previous case, we do not want to exclude manual tests in favor of automatic tests, or vice versa (at least until machines are able to pass the Turing test!).
