While in a large project, it was necessary to gap UI and backend implementation for several reasons. To manage that better, I developed the architectural blueprint for API connect and Gravitee; did the setup of the systems on OpenShift, defined and set up the toolset around (SwaggerHub) and defined the API strategy itself, including the technical part for SSO.
Take more time (had some other things to do as well), take the target system "naked" without any security means which, in the beginning, are a burden.