Differential Dataflow is about differential computation which itself is a generalization of incremental computing, most commonly known from Excel.
A good introduction to the overall topic is incremental [0] an OCaml library by Jane Street and the corresponding blog posts and videos [1]. They even use it for webapps [2].
[0]: https://github.com/janestreet/incremental
[1]: https://www.janestreet.com/tech-talks/seven-implementations-... (Great to understand fundamentals of an incremental computation graph)
[2]: https://www.janestreet.com/tech-talks/intro-to-incr-dom/