Although there is similarity, we are radically different.

We transform any existing databases MySQL, Postgres, SQL Server & SQLite databases into a spreadsheet. This is a _massive_ difference to begin with. And the ability to invite team to collaborate and build business workflow automations with Slack, Twilio is available for everybody. Since the launch today, I have already have close to 25+ plugin requests which sounds reasonable for NocoDB to have! We believe for a horizontal product like NocoDB - developing every app, connector and plugins is just beyond the ability of single team in open source. It is community driven approach that eases this possibility.

What would you say is the current upper bound on the number of records in a table that you support ?

There is no limit on upperbound - spreadsheet fetches data from your table in database.

Does it updates them in the database?

Yes it does which is what it makes it interesting.

Are there any schema assumptions, like numeric primary/foreign/surrogate keys?

We automatically identify all PKs & FKs

Yes! Exactly this. This builds an incredible toolkit that really brings the bicycle of the 21st century into view.