Take a look at Jarred's twitter, and you'll see he spends a lot of time profiling things: https://news.ycombinator.com/item?id=31993429 https://news.ycombinato

Take a look at Jarred's twitter, and you'll see he spends a lot of time profiling things: https://news.ycombinator.com/item?id=31993429 https://news.ycombinator.com/item?id=31993429 Of course, I can't say for sure that he looked at the fastest possible way to parse json here, but my intuition would be that if he didn't, it's because he had an educated guess that it'd still be slower.