Syncing Contacts for 2 Tenants

[DecimalZero]

Company A bought Company B. They each have their own Microsoft Tenant and do not want to merge companies. Both companies would like to share their contacts and calendars. Is there a tool for this or will I have to write some custom PowerShell to sync their Contacts and Calendars?

[#2]

PowerShell is free :) There are tools such as GalSync that can do cloud-to-cloud sync, of course at a price.

[#3]

Good information, thanks!!

[#4]

if you don't mind using a third party tool, there is this:
https://cloudiway.com/galsync/

[#5]

@DecimalZero 

3rd party tools is required and definitely PS can help