Thanks for the feedback.

0. Yes, I looked at Avro, Ion. I like Protobuf much better because I think using field numbers for field identity, meaning being able to rename fields freely, is a must.

1. Yes. Skir also supports that with binary format (you can serialize and deserialize a Skir schema to JSON, which then allows you to convert from binary format to readable JSON). It just requires to build many layers of extra tooling which can be painful. For example, if you store your data in some SQL engine X, you won't be able to quickly visualize your data with a simple SELECT statement, you need to build the tooling which will allow you to visualize the data. Now dense JSON is obviously not idea for this use case, because you don't see the field names, but for quick debugging I find it's "good enough".

3. I agree there are definitely cases where it can be painful, but I think the cases where it actually is helpful are more numerous. One thing worth noting is that you can "opt-out" of this feature by using `ClassName.partial(...)` instead of `ClassName()` at construction time. See for example `User.partial(...)` here: https://skir.build/docs/python#frozen-structs I mostly added this feature for unit tests, where you want to easily create some objects with only some fields set and not be bothered if new fields are added to the schema.

4. Good question. I guess you mean "forward compatibility": you add a new field to the enum, not all binaries are deployed at the same time, and some old binary encounters the new enum it doesn't know about? I do like Protobuf does: I default to the UNKNOWN enum. More on this: - https://skir.build/docs/schema-evolution#adding-variants-to-... - https://skir.build/docs/schema-evolution#default-behavior-dr... - https://skir.build/docs/protobuf#implicit-unknown-variant