Paolo ArdoinoVerified account

0.1 + 0.2 = 0.30000000000000004

Is that what broke Bitfinex this morning?

No lol. We don't use JS in the engine.

That said, it's not a JS thing. It's a floating-point thing. If you use floats instead of decimal types for financial math you're gonna have a bad time.

Yup. Ruby etc same thing. Just floating-point math, first thing everyone should learn. Still JS (ie. nodejs) would not be a smart move for a matching engine IMHO. Multi-threading is quite needed in order to reach large scale.

And while it has threads now - JS is never the right choice for a matching engine. Performance is too unpredictable, deopt still happens for seemingly random reasons, GC leaves a lot to be desired. Still beats python though for speed and convenience for most apps imo.

Indeed. Worker threads are quite slow. They don't allow 0-copy memory passing AFAIK. It's basically serialize/deserialize. Eventually I'll be curious to test this stuff. https://www.graalvm.org/reference-manual/js/Multithreading/ …