Discussion on: What are the benefits of writing automated testing?

Your unit tests are only ever going to be as useful as the person writing them, and the underlying code being tested in the first place.

They are not a silver bullet or a quality guarantee in your software.

Now, to discuss what I personally feel is the most valuable aspect of automated testing (specifically in the case of unit testing): test-driven-design.

This is a fairly radical restructuring of how you write code, by forcing you to write in a style that prioritizes understanding your execution as a series of inputs and outputs.

It encourages better software design by enforcing SOLID principles, with a heavy focus on SRP (single responsibility principle).

Writing software in this way naturally makes your solutions more resilient, with the added benefit of having automated tests to reinforce that.