Migrating from Axon Framework 4 to 5: What We Learned
A hands-on account of migrating a CQRS/ES application from Axon Framework 4.12 to 5.0 — the API upheaval, replacing sagas with stateful event handlers, and the reactive payoff.
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Propagating User Identity in Axon 5 Query Handlers
Why ReactiveSecurityContextHolder is always empty inside Axon query handlers, three approaches we considered, and the Axon MetaData solution that keeps query objects clean.
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The Silent Metadata Gap: Why Your Axon 5 Events Have No User Attribution
Command metadata doesn't automatically propagate to events in Axon Framework 5. Here's how CorrelationDataProvider fixes the silent data loss — and why it's so hard to catch.
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Testing Axon 5 Aggregates with Spock: A Practical Guide
How to test Axon 5 aggregate state machines using Spock and AxonTestFixture — from creation commands to guard clause rejections, with practical patterns for event chaining, timestamp handling, and injected services.
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