For database, we used firebase's realtime database: https://console.firebase.google.com/project/csc207-tli/database/csc207-tli/data
For registration, we used firebase's authentication: https://console.firebase.google.com/project/csc207-tli/authentication/users.
To host our backend, we used the google cloud platform: https://console.cloud.google.com/functions/list?project=csc207-tli Our front end is written in Java and our back end is written in Python.