I recently made a realization, that I can use MessagePack with a static schema defined in the code, and even pre-defined numeric field IDs, essentially replacing Protobuf for my use cases. I saw MessagePack as an alternative for JSON, with loose message structure, but it's actually a nice binary format and can be used more effectively than that. So now I enjoy things like tagged unions (in Zig/Python), and other types that are awkward to express in Protobuf. I settled on single character field names, for compatibility with msgspec, and I'm pretty happy with it. Still super compact messages with predictable schema, that are fast to parse, because I know which fields to expect.