merge join mendix data with backend data

Suppose an application which shows employer data and employee contractdata which resides on a backend system. The application retrieves this data through REST services and shows lists and details data on pages. There is some additional data for an employer or employee that isn't available in existing backend services. Example of additional data : a specific status on how much data of the employee contract is known, physical work locations for an employer. Is it a good idea to keep this additional data in the mendix application ? And merge/join the data everytime after the REST service is executed for the retrieval of employer or employee contract data in a microflow? (Merging would be done by keeping a backend employer id or employee contract id which would be stored at mendix side) Does somebody has experience with this kind of design?
1 answers

This setup will work, but you do have to think about which field is the unique identifier for that object. You can use that identifier to check if you already have that record and update it or that you should create a new object.

And in case this is Dutch data BSN is not allowed to use for unique identifier due to the AVG rules.