Explain the difference between the mindset required for test activities and the mindset required for development activities

The thinking of the tester and the developer has significant differences.

The main task of a developer is to design and create products. Therefore, the developer is more busy thinking through the creation of the product, rather than analyzing why it may not work.

The activity of the tester includes the verification and validation of the product, the search for various defects.

Therefore, a tester must have a healthy skepticism about the product being tested, and excellent analytical skills to successfully find existing defects in the product, as well as very good communication skills to convey the need for corrections to developers without conflicts.

Of course, developers can test their own code but from a psychological point of view, developers can be biased, overly well evaluating the quality of their product, so the involvement of third-party testers is definitely necessary in the process of creating large, complex or security-critical systems.