However, there are several facets to it.
From the system
Developers continuously run periodic integration tests, which lets them have constant feedback after changes have been made in the system.
From the customer/user
Primary feedback of the current state of the system is derived utilizing acceptance tests for users. It is continuously in place so that the user can steer the development process, with regards to available demands.
From the team
After the feedback from the customer is attained, the team immediately reverts back to the drawing boards to estimate timeline and cost involvement. Also, feedback on each other’s code is encouraged within the group.