The image shows the logical architecture with the following:

• Front-end tier: Browser
• On-premises or in a third-party cloud:
  • Back-end tier: Application Server
  • Database tier: MongoDB
• OCI region:
  • Back-end tier: Application Server
  • Database tier: Oracle Autonomous Transaction Processing Serverless

A MongoDB driver connects the Back-end tier and Database tier in each location (on-premises or third-party cloud and OCI). Content flows from the browser to the Application Server, then from the Application Server to the database in the Database tier in each location.

You can redeploy code without changes from the on-premises or third-party cloud Application Server to the Application Server in OCI.

You can migrate data and metadata from the MongoDB to the Oracle Autonomous Transaction Processing Serverless.