Is it possible to sync a local database with a cloud deployment? I am wondering if it is possible to connect a local graph database with a cloud deployment to work on when offline. This is more of a general curiosity...
I can only guess you would have to employ the same techniques as you would with any other database when you want to keep two systems in sync. You could run the local and cloud database as a cluster so as transactions are issued, that both instances receive the transaction. Or you do some sort of "log shipping" technique on the transactions so you can replay them later. And then a last option would be a backup/restore technique. For a small instance this would be the simplest approach. You can easily automate a script to backup one instance, copy the file, and then restore it to the target.
The clustering idea sounds like a promising option. Is this something you have done before?
You'll want to read up on the documentation https://neo4j.com/docs/operations-manual/current/clustering/. As with any cluster distance/network speed is going to come into play when transactions are being committed. For an on-prem to cloud cluster, if you're already with a little bit of latency, look into a casual cluster which would give you eventual consistency across your servers