Binary Event Serialization for Marten

This article explains the new binary event serialization feature in Marten 9.0, which allows individual event types to be serialized to a binary wire format (e.g., MemoryPack, MessagePack) instead of default JSON. This opt-in per event type improves throughput and reduces storage size for hot streams. The implementation adds a 'bdata' column to the mt_events table, with a discriminator to choose between JSON and binary deserialization. The article covers how it works, quick start with Marten.MemoryPack, registration ergonomics (attribute-driven and fluent), and compatibility with existing data and append modes.