If we were talking about Clojure, I would agree that 50x would indicate that something is off. But since we're talking ClojureSCRIPT, it doesn't surprise me.

Although, fair enough, it's a rewrite, and the author has the benefit of experience with the first implementation when writing this one. A second implementation in ClojureScript would likely have been faster than the first one. But 50x faster? Unlikely.

> Is WebAssembly faster than Javascript?

> Yes - about 50 times faster in my experience.

https://www.quora.com/Is-WebAssembly-faster-than-Javascript

Just as a data point that the author isn't the only one to see this type of performance increase.

I expect that it isn't 50x across the board over JS, but that it would vary wildly across the board, including being slower if you're doing something trivial and end up paying more in serialisation to and from WASM than you gain in speed.