Go support for Google's protocol buffers (by golang)
The classic answer is protobufs. You can serialize out to binary format.
NOTE: The number of mentions on this list indicates mentions on common posts plus user suggested alternatives. Hence, a higher number means a more popular project.
Protobuf - Go support for Google's protocol buffers
1 project | reddit.com/r/github_trends | 27 May 2022
2022-01-11 gRPC benchmark results
3 projects | reddit.com/r/grpc | 12 Jan 2022
2 projects | reddit.com/r/golang | 9 May 2021
Crowdstrike releases replacement for Gogo/protobuf
1 project | reddit.com/r/golang | 6 Apr 2022
jsoniter+1.18: panic in reflect2
1 project | reddit.com/r/golang | 16 Mar 2022