To help you prepare for the Google Professional Cloud Architect Exam, we have developed Project MoonBank with the goal of allowing candidates to design solutions based around the exam assessment goals of:
Designing and planning a cloud solution architecture
Managing and provisioning the cloud solution infrastructure
Designing for security and compliance
Analyzing and optimizing technical and business processes
Managing implementations of cloud architecture
Ensuring solution and operations reliability
Since this is a design/architecture project, there is no correct answer. The process of designing the solution, taking into the account the above goals, and discussing the solution is where the learning and exam preparation takes place.