Backward compatibility lets a newer consumer or implementation process data produced under an older schema. It matters when services evolve independently and must avoid silently dropped data, default values, or deserialization failures. section 12.2
Investigate compatibility when:
- A service adds a JSON field while another service still uses the older model. section 12.2
- A Protobuf enum is renamed or a field is not made optional. section 12.2
- A Java object is serialized with one version UID but deserialized with a different class. section 12.2
message Order {
int64 id = 1;
string customer_id = 2;
repeated string items = 3;
optional string notes = 4;
}
Use this Protobuf schema to inspect how fields are numbered, repeated, and marked optional while a message evolves. section 12.2
