What were the queries? Can you post them. Also, can you add the JSON latency data in addition to the ratio?
I hunch is that memory allocation is the issue here. We can also look through your code and see if there are any ways to optimize it.
If we want to spend more time on this, then we could dump the Flatbuffer responses in a file. Have a standalone script pick the response, run the PB and JSON converter, and calculate time. Go profiler could also help us dig into the real issue better, with this component isolation.
The other option is that we send back Flatbuffer response directly to Go client, and do the parsing in the client. That would surely be faster and more network efficient – but that’s a someday/maybe task if we really want to squeeze the extra juice for better performance.