Needs C# ASP.Net Zero developer to work on Xamarin mobile application and back-office webapp

We have a time management app built in Xamarin that is working concurrently with a back-end office web app. The mobile app is used by the field users who enter and submit data entries. The web app is used by the administrator to manage data on the mobile app and track data entries submitted from the mobile app. We need some support to build some features on the back-office web app, such as:

-Load new pay period from third-party payroll system to back-office app, then to mobile app
-Populate data entries from Xamarin app to back-office web app
-Other features as we go.