From CloudEvents to Domain Events

An airhacks.fm conversation with Johan Haleby about: discussion about the Occurrent event sourcing library for Java, motivation behind building Occurrent as a set of building blocks for event sourced applications, using higher-order functions instead of distinct framework concepts, the library approach for gradually introducing event sourcing into regular projects, CloudEvents as the serialized event format and its evolution into CNCF, real use cases including querying the event store for consistent reads and per-user logs, using the CloudEvents subject attribute to index a user, enforcing unique constraints such as one email per person, dynamic consistency boundary, event sourcing fundamentals of storing a list of events instead of mutable state, basing decisions on prior events, the distinction between event sourcing, CQRS and CQS, materialized views and different read and write models, subscriptions to events after they are persisted, the difference between domain events and integration events for decoupling teams, auditing versus event sourcing and why intent matters, Hibernate Envers, Transaction Script pattern, folding events into state with Java Gatherers fold, modelling domain logic with sealed interfaces and records, static decision methods returning new events, the Redux analogy, snapshotting and closing the books for long streams, Kafka and Kafka Streams for event-driven architecture, cascading enriched events, ksqlDB materializing streams as tables, DynamoDB Streams and on-demand tables, storing state alongside events in one transaction, tractors and fitness trackers as event sources

Johan Haleby on twitter: @johanhaleby