A marketplace admin has to-     

1.Configure inventory settings in the multi-vendor marketplace. 

2.Set global commission for the sellers or set a separate commission for an individual seller. 

3.Approve or Disapprove, the status of any transaction. 

4.Generate invoices and ship the product to the seller if it's desired.

5.Approve and manage seller reviews given by customers once an order is completed, an admin can create a “Payout” for the seller. 

6.Enable or disable the vendors/sellers 

7.Approve or disapprove products uploaded by the sellers. 

8.Build an attractive landing page with top sellers and their associated top products.