BackendData/ML/AIAround since 2008
Protocol Buffers
Also written as Protobuf, proto3, Avro
A compact, strictly-defined format for sending data between services — smaller and faster than JSON, but both sides must agree on the shape in advance.
Think of it like
A pre-printed form with numbered boxes, versus a handwritten letter. Less flexible, far quicker to process.
Junior or senior?
Usually appears alongside gRPC.
Senior sounds like
Has dealt with evolving a schema without breaking services still running the old version.
Ask them
“How did you add a field without breaking services that hadn't been updated yet?”