Nim's default json library is terrible in performance, but there're much faster drop-in replacements like jsony[1]. I'm not sure that's the main issue for low rank, but it's definitely one of them.

1. https://github.com/treeform/jsony

Interesting. The Vercel benchmarks make it look pretty good. Only slightly behind rust. https://programming-language-benchmarks.vercel.app/zig-vs-ru... Benchmarks are as much about the skill of the programmer as they are about the language. I suspect those numbers could improve drastically.

httpbeast[1] reached #6 at one point, but I think the author is busy with other things nowadays.

https://www.techempower.com/benchmarks/#section=data-r18&hw=...

[1] https://github.com/dom96/httpbeast

Possibly it wasn't compiled with `-d:release`. I only looked briefly — is there a way to see the source code and cli flags used for the various implementations?

For reference, here's some other benchmarks which show happyx (a Nim framework) to come on top: https://web-frameworks-benchmark.netlify.app/result

It isn't really a language community so interested in web server efficiency, and until recent years threading efficiently was kind of tricky with the GC scheme they used. If someone wanted Nim to rank high you could do it, but I'm not sure it is worth the effort?