Why Avro and Schema Registry? JSON has no schema enforcement — a producer can change a field name and silently break every consumer. Avro + Schema Registry solves this: Avro gives you a compact binary format with a schema definition Schema Registry stores and versions schemas, enforces compatibility rules, and prevents breaking changes from reaching consumers flowchart LR subgraph Producer["Order Service"] E["OrderPlacedEvent"] -->|"KafkaAvroSerializer"| SR["Schema Registry\n(register/lookup schema)"] SR --> Bytes["[schema_id (4 bytes)] + [avro payload]"