The tl;dr based on this talk[0] by acdlite is that they're looking to separate out high-priority and low priority rendering, so you don't end up (for instance)

The tl;dr based on this talk[0] by acdlite is that they're looking to separate out high-priority and low priority rendering, so you don't end up (for instance) with animations that are janking because item #12,141 in your list hasn't rendered yet. They're using requestIdleCallback and requestAnimationFrame to schedule the work. Sounds like the architecture of fibers themselves is very heavily inspired by the way a call stack is implemented. [0]: https://youtu.be/aV1271hd9ew https://youtu.be/aV1271hd9ew