From your team, those should be the people who are most familiar with the idea and vision of your project and who will be involved in the execution. Our team provides a facilitator who will guide everyone through the process. Additionally, our senior UX/UI designers will be responsible for the project, and a senior developer will advise on the technical aspects of requirements and features.
You can also let us know if you feel that some people from your team should only be included in some parts of the workshops. However, if the workshops are longer than one session, at least one of your team members from the previous session must be present.