https://www.youtube.com/watch?v=OsyKxWxGtiI Your API returns a user. Three fields — an ID, a name, a bit for active. That exact payload, as compact JSON, is forty-one bytes on the wire. As protobuf, it's twelve. But compactness is the least interesting thing about protobuf. The real reason Google built it is something JSON fundamentally cannot do. The JSON bill you pay on every request Take this