I've also written and tried to optimize a hand-rolled JSON parser for exchange messages, just to see how fast pure JS could go. I tried many different things, b

I've also written and tried to optimize a hand-rolled JSON parser for exchange messages, just to see how fast pure JS could go. I tried many different things, but I only ever got near to the native implementation once I started assuming certain offsets in the buffer or optimistically parsing whole keys which were highly unsafe. My verdict was that you will never really get close to native, let alone close to hand-optimized C/C++.