Hi, sounds like an interesting project! With a brief like this I usually take an agile approach to the design process, which is easy to follow and keeps the communication lines opened, eliminates mistakes and enables a quick delivery of your project.
1. INITIAL CONSULTATION: to establish the strategy, purpose and success metrics of the given project
2. RESEARCH: After initial consultation I do my usual research ( User Stories, Personas, Competitors, Architecture Styles, Features etc.)
3. SKELETON: Starting with Flow Charts / Mapping, then onto basic Black & White sketches (wireframes), then onto Style Guides (Branding, Color Scheme, Icons & Typography)
4. INTERACTIVE PROTOTYPE: once we agree on all the aspects of the wireframes, I build an interactive, high fidelity prototype for final testing and approval