> several data formats using custom binary and several data formats using JSON You may not realize it, but you've presented a false dichotomy here. The altern

> several data formats using custom binary and several data formats using JSON You may not realize it, but you've presented a false dichotomy here. The alternate to JSON isn't "custom binary", it's standardized binary encodings that allow the same flexibility (or additional flexibility) compared to JSON. Some examples include cbor & msgpack. >> Write programs to handle text streams, because that is a universal interface. cryptsetup manipulates block devices. I don't think that line can or should really be applied to something that is fairly similar to a filesystem's on-disk format.