How should I build the architecture of my MongoDB database?
Should I use MongoDB for real-time changes (updates) in this project?


Yes, you can use MongoDB for real-time updates. There are two options available for real-time updates based on whether you are using MongoDB Atlas(Fully Managed Cloud MongoDB service) or Self managed MongoDB service.


Self Managed(On-Prem/Cloud) - From MongoDB 3.6 the new feature Change Streams got introduced. Change streams allow applications to access real-time data changes without the complexity and risk of tailing the oplog. Applications can use change streams to subscribe to all data changes on a single collection, a database, or an entire deployment, and immediately react to them.
MongoDB Atlas - This comes with a service called Stitch Triggers. This will enable you to execute application and database logic automatically, either in response to events or based on a pre-defined schedule. This is the backend uses the Change Streams functionality.


So MongoDB should be a perfect option for your requirement.