Urgent: Google cloud architect required

We need to develop a serverless web application using GCP.
This application is an Employee Leaning management and talent management system.
The system will get the data from various other systems through APIs.

I need a highly scalable serverless architecture based on GCP.

Frontend : React Native Mobile app and React Web portal.
Backend: Node.js
Database: MongoDB to any suitable Google Database.


Regards,
Ashutosh.