[your_fin]

If you haven't seen it, I'd recommend checking out Amazon's Ion data format: https://amazon-ion.github.io/ion-docs/

It's schemaless, so the binary format can't be as effecient as protobufs, but IMO the minor overhead is worth not paying the costs protobuf has to.

The text format (which is interoperable) is a strict superset of JSON that resolves many of the issues ziggy tackles (tagged unions, comments, verbosity, multiline strings), although not quite as prettily for configs.