There are not exactly three roles in ATDD, but rather three key perspectives involved:
1. The Business: Represents the stakeholders who define the desired functionality and acceptance criteria. They are responsible for creating user stories and acceptance criteria.
2. The Developer: Responsible for writing the code and implementing the features. They work closely with the business and testers to ensure that the code meets the acceptance criteria.
3. The Tester: Responsible for creating automated tests that verify the functionality of the application. They work closely with the business and developers to ensure that the tests are comprehensive and accurately reflect the acceptance criteria.
Collaboration is key in ATDD. All three perspectives should work together throughout the development process to ensure that the final product meets the needs of the business.
It's important to note that ATDD is a collaborative approach and individuals might wear multiple hats depending on the team structure and the specific tasks at hand.