Will Umbraco a good choice for…

Hi, this is my first post in this new umbraco community home.
We work on Umbraco since 1.0 version
Today we have a new hard task. wish a your suggestion if Umbraco could be a good choice to build a data manager to manage al leader 5k members, each members should have a parental relation eith other members, they must insert reimbursement procedures and related documents, the back office must validate the procedures, etc. Then we have to build external modules to other jobs. Members will use external UI. We like the flexibility of the documentare type and sull’ use Auth0 as IdP. Thanks.

Any help? …