When redesigning such a key part of the purchase process as the check out for different versions, it is necessary to test all of them: app, mobile and desktop. Since the type of user that interacts with each one is different and their way of buying differs depending on the time of purchase and the device. To achieve a successful testing it is necessary to work together and aligned with the design and IT team, involve them in the development of research materials and be present during testing. This helps them to get out of their designs and observe first-hand how the user interacts with the prototype and they can validate their hypotheses in first person. Although it is then necessary that the research expert is the one who prepares the report of results and draws the insights and conclusions.