A few years back, to showcase a proof-of-concept to a potential customer in a short timeline. We started working on the design and data model at the same time. Expecting the changes from the design would only affect the screens and UI state, but eventually, it changed the data model as well.
Learning: Do not work on the data model before the Information Architecture (IA) stage of the design.
Designers play the role of a catalyst; they must have empathy towards all the functions of the business. I have created an infographic to depict the relationship with other stakeholders.