My process includes the whole team from the beginning. This is a practice that has been reinforced by my collaborations with Apple at design sprints and in training at LUMA Institute.
While I focus on users as primary stakeholders, I also engage project managers, developers, writers, and the QA team members, each of whom brings expertise in unique corner cases that benefit from early exposure.
I strongly believe in establishing a friendly collaborative culture before interruption can create friction between teammates. User experience is a reflection of the production experience. Stress-free solutions come from teams that openly and gladly address interpersonal dynamics.