ATDD

Acceptance Test-Driven Development (ATDD) is a software development approach in which the acceptance criteria for a feature are defined and automated before coding begins. It emphasizes collaboration among product owners, testers, and developers to ensure a shared understanding of what the software should do and how it will be evaluated. The acceptance tests serve as a contract between stakeholders and the implementation team and are designed to be automated so they can be run repeatedly as part of the build and release process.

The typical ATDD process starts with identifying a feature and writing acceptance tests that describe the desired behavior from the user’s perspective. These tests are often written in a Given-When-Then style and focus on business outcomes. The tests are then automated and integrated into the continuous integration pipeline. ATDD complements unit testing (TDD) by focusing on feature-level acceptance criteria rather than code-level correctness.

ATDD is closely related to behavior-driven development (BDD); many teams use the terms interchangeably or merge practices. In practice, acceptance criteria are expressed as executable specifications that non-technical stakeholders can understand, serving both as tests and living documentation of intended behavior.

Benefits of ATDD include improved alignment among stakeholders, clearer scope, and faster feedback, while potential drawbacks include the overhead of writing and maintaining acceptance criteria and tests, and the need for disciplined collaboration. Tools commonly used for ATDD include Cucumber, SpecFlow, JBehave, and FitNesse, which help translate scenarios into automated checks runnable within CI pipelines.