[sujayakar]

hi! sujay from convex here. I remember reading about your "reverse query engine" when we were getting started last year and really liking that framing of the broadcast problem here.

as james mentions, we entirely re-run the javascript function whenever we detect any of its inputs change. incrementality at this layer would be very difficult, since we're dealing with a general purpose programming language. also, since we fully sandbox and determinize these javascript "queries," the majority of the cost is in accessing the database.

eventually, I'd like to explore "reverse query execution" on the boundary between javascript and the underlying data using an approach like differential dataflow [1]. the materialize folks [2] have made a lot of progress applying it for OLAP and readyset [3] is using similar techniques for OLTP.

[1] https://github.com/TimelyDataflow/differential-dataflow

[2] https://materialize.com/

[3] https://readyset.io/

[rockwotj]

Yeah I like the model of the full function becomes the point of reactivity. It's very different than Firestore (which is trying to sync data to the device so it can run locally). It does allow Firestore to have some better offline behavior by computing queries with cached data locally, but there are benefits (which the article points out) to remote execution too.

I wish y'all the best I do think this is a super cool product!