How’s your experience building collaboration tools (like Figma)?

I’m thinking of developing multiplayer experience on my app, where multiple users can modify a shared ‘whiteboard’ in real time. I’m aware that there are companies creating multiplayer experiences on top of their existing product (Figma, CodeSandbox), and some that have it from the beginning (Observable for example). So, I know it can be done no matter what stage the product is at. However, there’s not many online resources on how it can be done (and how hard), besides a nice article from Figma (https://www.figma.com/blog/how-figmas-multiplayer-technology-works/) and fairly theoretical literature on Conflict-free Replicated Data Types (CRDT).

Do you have any experience building such a feature? Where should I begin? What would you recommend?

For context I’m a full-stack engineer and have used React Typescript and a couple of backend tech (Java, Go). Thank you :)