Apache Avro is a compact, schema-based, row-oriented serialization format — the default encoding for Kafka pipelines and schema-registry workflows.

Protocol Buffers (protobuf) is Google's language-neutral, schema-first binary serialization format, ubiquitous in service APIs and increasingly present in event streams.

Apache Parquet is the standard columnar file format for analytics — compressed, splittable, and readable by effectively every engine, table format, and data tool.