canvas-datagrid

I'm biased because I'm the maintainer, but canvas-datagrid is a, uh, canvas-based datagrid (https://github.com/TonyGermaneri/canvas-datagrid), which can easily handle millions of rows. It's FOSS, and although in need of improvement (and better type annotations), it's well-documented (https://canvas-datagrid.js.org/) and actively maintained.

The Cells example is super interesting to me, because I've longed for an open source, liberally licensed, spreadsheet component for the web, similar to what exists for rich editing (ProseMirror, Slate, Quill). Some UI frameworks like Material UI have a neat table component, but the pro version gets the fancy data grid, and it isn't designed to be able to function as a spreadsheet anyway. Besides lacking an open source version, spreadsheets and data grids haven't been studied as well as they should be. It is also difficult to build one using just the DOM. For instance, you can't have a table be horizontally scrollable with the scrollbar fixed at the bottom and also have a fixed header. Here's something I played around with a while back that has keyboard navigation between cells. Going between pages isn't great. The default focus scrolling

An excellent decision, I guess. I'm somehow thinking way too much about such details instead of starting any project. In my previous job, we have used PHP at the backend, but somehow, I like the syntax of python much more. And the community and number of projects around Django are just mind-boggling. So you are probably using Django-REST for the API? With react-virtualized, you are already on the right path as virtual rendering - rendering only the currently visible cells - is the key in regards to the performance of DOM-based approaches. But if you want to reach google sheets performance, there is probably no way around canvas-based rendering (e.g. https://github.com/fin-hypergrid/core or https://github.com/TonyGermaneri/canvas-datagrid). Office 365 seems to use a canvas-based approach as well. The problem with the canvas-based approach

Check out canvas-datagrid: https://github.com/TonyGermaneri/canvas-datagrid I'm using it to mimic Excel-like display of data, and it's pretty responsive, but I'm not at your scale of 10x/sec. It also supports cell highlighting with different colors, but, unfortunately, doesn't natively support CSS-type classes on cells.

If you're interested in this, also check out canvas-datagrid. https://github.com/TonyGermaneri/canvas-datagrid