They've already implemented a lower-level protocol "we fork/exec your binary, it needs to bind to port _LAMBDA_SERVER_PORT, and it must follow gos net/rpc proto

They've already implemented a lower-level protocol "we fork/exec your binary, it needs to bind to port _LAMBDA_SERVER_PORT, and it must follow gos net/rpc protocol". aws provided a library, aws-lambda-go, that every go implementer must use. Anyone can implement their own 'aws-lambda-go' library in what ever language they want, but the choice to use net/rpc and it's gobs format makes it more difficult than it could be. json is implemented in practically every language. there are binary formats with libraries is most languages if your want to be efficient. Choosing a protocol other than net/rpc would 1. make it easier for AWS to support more runtimes 2. make it easier for the community to support custom runtimes. 3. be as easy to integrate with as aws-lambda-go is.