Under the hood, the spreadsheet engine is a columnar key-value store written in Rust. We built it from scratch because SQL engines like DuckDB only work well for structured tables. The unstructured nature of spreadsheets make them a bad fit for SQL. The engine also needs to be 100% Excel compatible so you can import existing xlsx files.
The front-end is a big React app with hand-rolled canvas rendering. We virtualize scrolling to handle 2 billion+ row data sets. All workbook state runs in the cloud (located in a data center close to you to keep things snappy).
We launched on HN 2 years ago and got lots of great feedback. Since then, customers have pulled us towards the enterprise. Today we're launching Row Zero 2.0 with support for all the enterprise bells and whistles: OAuth database connections, SSO, SCIM, workspaces, private link on AWS and Azure, bring your own AI key, and private storage. Excited to hear what you think.