There exists a peculiar amnesia in software engineering regarding XML. Mention it in most circles and you will receive knowing smiles, dismissive waves, the sort of patronizing acknowledgment reserved for technologies deemed passé. “Oh, XML,” they say, as if the very syllables carry the weight of obsolescence. “We use JSON now. Much cleaner.”
If both sides have a shared data model it’s a good base model without further needs. Anything else quickly becomes complicated because of the dynamic nature of JSON - at least if you want a robust or well-documented solution.
If the sides don’t have a common understanding of the data structure, no format under the sun will help.
The point is that there are degrees to readability, specificity, and obviousness, even without a common understanding. Self-describing data, much like self-describing code, is different from a dense serialization without much support in that regard.
Yeah, when the same API endpoint sometimes return a string for an error, sometimes an object, and sometimes an array, JSON doesn’t help much in parsing the mess