Not books, but some inspiring resources. FModel [0] is a set of patterns for functional reactive DDD on the basis of event sourcing. In particular the Decider pattern is a great way to model aggregates, and test them using Scenario's that read like Gherkin in code (given.. when.. then). Combines well with actors to represent aggregates.

On the BEAM used by Erlang, Elixir, and Gleam actors are called processes, and this guide [1] delves into domain modeling with them.

[0] https://fraktalio.com/fmodel/

[1] https://happihacking.com/blog/posts/2025/the-gnome-village/