At the moment I would say Strymonas is a tech demo. If I was reviewing the code there would be a lot of comments along the lines of "seal this trait", for example.

I would expect it to be very much faster than Akka Streams. It has quite a different design as far as I can tell, and doesn't support things like distribution across machines.

I am not closely familiar with Akka.Streams but can give you an intuitive explanation about what is new in Strymonas: the computation flow described with functional combinators like map, take and filter is represented as staged data ('a code type in OCaml), this means that what you get is not an actual computation but just a declarative description of all the steps. During compilation the combined code data structure is encoded as a simple loop or unfold computation.

Does that help?