In Agile development, testing is typically:

In Agile development, testing is an integral part of the process that occurs during every iteration. This continuous integration of testing helps ensure that issues are identified and addressed promptly rather than being deferred until a later stage. By embedding testing into each iteration, Agile teams can validate functionality, gather feedback, and improve the quality of the product incrementally.

This approach allows for greater flexibility and responsiveness to change, which are core principles of Agile methodologies. Testing frequently within iterations facilitates a collaborative environment where developers, testers, and other stakeholders work closely, leading to early detection of defects and alignment with user requirements. Additionally, this practice helps maintain a sustainable pace and supports continuous delivery of value to the customer throughout the development lifecycle.

Other approaches, such as conducting testing only at the end of the project or keeping it to a separate phase, go against Agile principles by introducing delays in finding and fixing defects. Similarly, limiting testing to just acceptance testing does not capture the full scope of testing needed to ensure product quality throughout the development process.