Wroclove.rb 2018 lightning talk, presented as a short follow-up to the speaker's earlier talk about commands and events. Sketches a minimal command/event bus: a boot-time registration phase where command handlers (one per command) and event handlers (multiple per event) are added to a registry, and an execution phase where the publisher simply asks the bus to handle a command or event. Argues this fully decouples publishers from handlers: publishers don't know what will handle the message and handlers don't know where messages come from. Speaker is honest that they are unsure whether this is a good idea — it's a pattern used sometimes — and invites the audience to share opinions.