Avro has a solution to this that I always thought was quite elegant. Schemas are external (serialized data isn't self-describing) but the library exploits this

Avro has a solution to this that I always thought was quite elegant. Schemas are external (serialized data isn't self-describing) but the library exploits this to it easy to read and write old versions. To quote the documentation: The library provides "a resolving decoder, which accepts calls for according to a reader's schema but decodes data corresponding to a different (writer's) schema doing schema resolution according to resolution rules in the Avro specification." Those resolution rules are defined here: https://avro.apache.org/docs/current/spec.html#Schema+Resolution https://avro.apache.org/docs/current/spec.html#Schema+Resolu... The downside, of course, is performance.