Like Bulk contact API to create or update group of contacts at a time. Is there an RESP API to upload group of companies and group of engagements(Notes).
There isn't currently a company bulk create endpoint, though I can totally see the use case for that, though; If you have the inclination, I would encourage you to check out the Ideas Forum on the HubSpot Community. There, you can create a post including your use case that product and other customers can see.