I have 4 repos.
All the backend work is in one repo. The monolith has everything including the core API services, background/batch processing, etc.
I have a mobile repo but we aren't ready at all yet to work on mobile. It is a flutter app, but mostly proof of concept type stuff.
Then there's 2 repos for web UI. One is a next js app for generating applications for customers, and the other is a standard react SPA which is what customers use to build their applications.