In the previous post, we established that as long as ruby/json wasn’t competitive on micro-benchmarks, public perception wouldn’t change. Since what made ruby/json appear so bad on micro-benchmarks was its setup cost, we had to find ways to reduce it further. Spot the Seven Differences So I decided to file this performance discrepancy as a bug, and investigate it as such and started profiling Stephen’s micro-benchmark with both ruby/json and oj: benchmark_encoding "small mixed", [1, "string", { ...