This is not a “greenfield” development, but we are already adopting a finished application that we are modernizing. At the moment, it is written on IBM technologies
We do a monolith breaking through ESB, which will use the opensource product WSO2 and also the interface logic written in Java.
Portal solutions run as a single page application on the angular framework. The individual business logic is designed in the form of microservices to run in containers (not yet implemented).