Ask HN: How to build infinite grid in the browser?

If you wanted to build a tool in the browser that allowed you to add, edit, connect, and move elements on an infinite grid like 1) https://natto.dev/example/2444ffca064a4890a7f05ca1de386c5a and 2) https://stately.ai/registry/new, where would you start? How would you build an infinite grid? I kinda expected to find an open source library with the base functionality, but I've turned up nothing so far.