How to build a web portal like application without portlets?

We want to build a large customer web portal for our customer care rep and end customers. The web portal has multiple functionalities like Case mgmt, customer mgmt, reports, Trouble shooting tools,etc. Each of these are built by separate team but the portal is to be hosted/deployed/accessed using one url and the portal should have SSO to navigate across these functionalities/modules. Each of the modules can be built and hosted in separate servers. What are the alternatives to build such web application where multiple teams can make releases independent of each other. Less scenarios to merge source code. Note the technology stack is AngularJS for UI and Spring Rest API for backend server. Any design proposals will be appreciated.

One Option is each of these functionalities will be modeled as tab and within each tab we have an iframe which gets data from separate app server.