Parsers like simdjson output a sequence of tuples, not trees. You can do a lot with that even if you need a tree in the end because you can filter the stream f

Parsers like simdjson output a sequence of tuples, not trees. You can do a lot with that even if you need a tree in the end because you can filter the stream first, thus using very little memory until you get to the part you're interested in, which you then hydrate by constructing the equivalent tree using just that part of the stream.