As you might guess, at this stage, the developed feature is checked. The main testing method in hh is exploratory testing. This is a type of testing that does not require writing test cases, but implies that each subsequent test is selected based on the previous ones.
This does not mean that the tester randomly pokes buttons and sees what happens. Unfortunately no. This method requires a lot of experience from the tester and very good knowledge of the product. The main advantages of exploratory testing, which we highlight for ourselves:
Does not require support and writing test cases;
We are not subject to the so-called pesticide paradox;
Increased testing speed.
The next step is development itself. In many companies, at this moment, testers leave to write some kind of test documentation, test cases, or update something. At this moment, we are intensively writing autotests. But not for new functionality, but for the one that already exists, I went through certain A / B experiments and so on. There is always something that is not covered by tests and is in dire need of them. Also, we may have unstable tests or tests that need to be updated. You can do them too.
But we do not always wait for the full cycle of the completion of the development of a particular feature. A tester can take a build already somewhere in the middle of the process, if a partially working functionality is ready there, and see how it is implemented. Indeed, even at this stage, problems can already occur, and the sooner we notice them, the better.