Audience (a self-described event-sourcing proponent) asks whether event sourcing remains more expensive in the long run and how to bring its cost down. Davydov: in the short term it's slower than a CRUD prototype, so startups searching for funding are often better off without it. Companies that switch do so with eyes open and accept upfront pain for long-term benefits. He often meets developers (e.g. a Java friend) who already use something like event sourcing without knowing the name — tracking systems naturally resemble it. To reduce cost: (1) more learning — blog posts, workshops, conference talks; (2) better tooling for debugging event-sourced systems.