I have not used it myself but colleagues of mine recommend k6: <a href="https://k6.io/open-source/" rel="nofollow">https://k6.io/open-source/</a><p>There is also a Github repository keeping track of all the load-testing tools out there: <a href="https://github.com/denji/awesome-http-benchmark" rel="nofollow">https://github.com/denji/awesome-http-benchmark</a> You will probably find something that will fit your bill.<p>I do not understand though why it is of any relevance what language the application is written in. Yes, Go and Rust indicate a certain speed and novelty but you can write fast applications with good UX in other programming languages too (and bad ones in Go and Rust).
I've used LoadForge before for stress testing:<p><a href="https://loadforge.com" rel="nofollow">https://loadforge.com</a><p>I found it a good middle-ground between DIY tools like "hey" and the likes of JMeter and K6.<p>LoadForge is really just a frontend for Locust [2] behind the scenes so all tests are written in Python which might not fit your requirement for Go/Rust, but it's affordable and quick to get started with.<p>[1] <a href="https://github.com/rakyll/hey" rel="nofollow">https://github.com/rakyll/hey</a>
[2] <a href="https://locust.io" rel="nofollow">https://locust.io</a>
I suppose the end goal is to replicate production traffic patterns as close as possible. Why not just use production traffic? Of course omitting PII is mandatory.<p>Take a look at goreplay. <a href="https://github.com/buger/goreplay/wiki" rel="nofollow">https://github.com/buger/goreplay/wiki</a>