раст энтузиасты таки замахнулись на вотчину кафки
https://www.fluvio.io/

что удивительно

Compatible with Kafka - Works with Kafka client and server APIs.

Despite how functional programmers often talk about it, mutable state is a fundamental part of programming, and one that cannot and should not be done away with. Sending a network packet or writing to disk are examples of mutability. A complete commitment to immutability is a commitment to never building anything real.

Mutable state has its costs, however. Mutation-free code is generally easier to reason about, making interactions and dependencies between different parts of your codebase explicit and easier to manage. OCaml strikes a good balance here, making mutation easy, but making immutable data structures the default. A well-written OCaml system almost always has mutable state, but that state is carefully limited.

Животное убогое