The company I work for does IT for a bunch of small to medium sized companies. We are in the process right now of converting one over to 365. If you are talking about backing up their systems, we use a combination of OneDrive and Synology.
If you are talking about backing up their full on 365 in the cloud, I didn't even know that was a thing. I would like to know more.
I signed up for lemmy when Reddit started pulling it's shit. But I didn't really do anything here until today when sync informed me that the lemmy app was available.