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Comment by Cthulhu_ | Hacker News Reader

> If you actually needed performance you couldn't use a garbage collected language.

This is incorrect; HFT platforms have been written in Java for example (https://news.ycombinator.com/item?id=24895395). But it's about either tweaking GC settings or mode, or avoiding using the heap entirely if you can.

Go is still slow if you (over)use the heap, but at least it gives you the choice and plenty of tooling to analyze it.

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HFT’s have the luxury of a 9am-4:30pm ET trading window and memory being relatively cheap. But things like self driving cars don’t have that luxury.

I really like the arena libraries you can use in Rust where you can have logic to free untouchable memory at a specific time.

Which is why real time GCs aren't free beer.

https://www.ptc.com/en/products/developer-tools/perc

https://www.aicas.com/wp/products-services/jamaicavm/

Isn't it like... literally just that one HFT company that did this? I've seen it pointed at for years, but afaik the vast majority use C++.

Many companies did this in the past. Nowadays Java, Go, etc GCed languages are still used but not for the hot path anymore. They are a couple million times slower than what we need.

No. There's one that made noise about it, but I personally know more than one other from working on their code. Not going to name anyone because I'm not sure they want their tech decisions publicized.

Also some performance-sensitive chunks of wall street itself (depending on how you define "wall street itself". And "performance sensitive" (what I worked on was more "high throughput" than "no pauses".).) run on java.

TBF, I write a lot of java, so my perspective is probably biased, but I can assure you, it's out there.

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