Distributed log/streaming platform that some companies use to store events (with log compaction). Pašalić doesn't recommend it as an event store after hearing horror stories, though in his prior advertising-industry work the team used Kafka-like projections and compacted everything at the end of each campaign. Davydov mentions Kafka-style compaction as one way (though 'not a true way') to effectively delete user data in event-sourced systems, and notes a 'karafka' Ruby gem for Kafka integration.