What @pluc said basically. You could use stuff like https://bte.mills.io and https://git.mills.io/prologic/squint to help test/validate the "behaviour" of what is being developed/built. Try to think of yourself as the "Product Designer" and "Product Owner". Worry less about the _actual_ code itself, and more about how the software/product behaves. Write specifications that can be validated and ask yoru favourite coding assistant to ensure that those are validated.