We recently implemented NextCloud in our organization, and it has been great so far. Completely free and opensource. It has a whole suite of applications for it, but its main bread and butter is the Files app. It should be able to do what you requested with one of the workflow apps. It lets you do a number of actions on a file based on pretty much any criteria you can think of.
I have a company looking to consolidate a few of their systems into a centralized portal, which both internal and external users can access to upload documents, which then has some logic built in.
This is a financial company, which would like to be able to have a portal, which not only requires the file name conform to their naming convention, based on their criteria, but would also like there to be an option of selecting a number of different documents they require the customer to upload, and then when the customer uploads those types of files it notifies staff, and further will keep reminding the customer to upload documents if not uploaded.
I know this system would probably need some customization, but was curious if anyone knows of a good solution that does something similar already, or at least something similar??
Thanks for any assistance.
