I've never done load testing before, but would it be hard to write a script in pure ruby (maybe with a few libraries) that makes a lot of concurrent requests to whatever endpoints and using whatever params you like?
Once you've got that out of the way, don't forget that you'll want a distribution story. It does not matter how efficient your tool might be on a single machine - you'll want to distribute your tests across multiple clients for real-world testing.
"Sure it's easy" you might say, "I know UNIX. Give me pssh and a few VMs on EC2". Well, now you've got 2 problems: aggregating metrics from multiple hosts and merging them accurately (especially those pesky percentiles. Your tool IS reporting percentiles rather than averages already, right?!), and a developer experience problem - no one wants to wrangle infra just to run a load test, how are you going to make it easier?
And, this developer experience problem is much bigger than just sorting out infra... you'll probably want to send the metrics produced by your tool to external observability systems. So now you've got some plugins to write (along with a plugin API). The list goes on.
I'm very biased, but it's 2024. Don't waste your time and just use https://www.artillery.io/
1. https://www.artillery.io/blog/load-testing-workload-models
Not saying everyone has nefarious reasons for doing it, but, it's just... everywhere.
I also play guitar, and there is a popular store in Europe with a pretty dang popular YouTube channel that I sometimes watch when the topic seems interesting. There was a whole kerfluffle a few months ago because one of the brand names that was getting a lot of air time on their YouTube channel was one that was financially backed by the owner of the store and a host of the channel. It took a ton of research of another YouTube to uncover this, and after it was found out, the owner of the store and host of the channel, finally disclosed his relationship with the brand he was promoting.
I feel like this was my more eye opening moment that tons of people out here on all variety of services are recommending their products but not disclosing their relationship clearly.
Now, you are saying so in your profile, but how many people are going to click into your profile?
I'm not saying you _have_ to do this, just suspecting that there are more and more people who are giving every recommendation the side eye these days because lack of disclosure. Disclosure isn't a bad thing, it just puts the bias in the open and people can gauge the recommendation more easily with that bias in mind.
None of this is probably new to you, but, trying to add something to the conversation rather than just call someone out, which is the easy and far more violent thing to do.
Shameless self promotion but I wrote up a bunch of these issues in a post describing all the mistakes I have made so you can learn from them: https://shane.ai/posts/load-testing-tips/
> Finally for full scale high fidelity load tests there are relatively few tools out there for browser based load testing.
It exists as of a few months ago and it's fully open source: https://github.com/artilleryio/artillery (I'm the lead dev). You write a Playwright script, then run it in your own AWS account on serverless Fargate and scale it out horizontally as you see fit. Artillery takes care of spinning up and down all of the infra. It will also automatically grab and report Core Web Vitals for you from all those browser sessions, and we just released support for tracing so you can dig into the details of each session if you want to (OpenTelemetry based so works with most vendors- Datadago APM, New Relic etc)
If your desired load for testing is small, it's not a big deal, of course.