DonJuanDiMarco wrote:
I have found this folder where a process intelligenceplatformd is being very active, seems to log data into structures called Graph and Onthology. Does anyone know what this is for? If this is part of MacOS, which part? Siri?
I am on Ventura.
Part of the macOS, yes
SQLite data base used by Core Data based apps and these files store in-flight transactions for the main file.
if you are running macOS Ventura you should see this folder in your user Library

I do not recommend deleting these cache files
you may receive more insight if you research on your issue in the developers forum:
Developer Forums - Apple Community