If you don't need versioning nor compatibility with other architectures, save the data directly as binary into a file. If you need versioning or compatibility (

If you don't need versioning nor compatibility with other architectures, save the data directly as binary into a file. If you need versioning or compatibility (x64 vs x86 or low endian vs high endian) you need to convert the data using json, cbor, some custom format or anything else.