[maxime_cb]

YJIT is optimized primarily for web workloads. We look at rails performance a lot, but also at various other libraries that are used in that context. If you look at the headline benchmarks at https://speed.yjit.org, it will give you an idea of what we're mostly focused on. This is in contrast with academic compiler project, which often focus on microbenchmarks and code that is very different from the code users actually run in practice.

YJIT or TruffleRuby: I'm biased being that I work on YJIT. The nice thing about YJIT is that it's likely to work out of the box, and just be a matter of calling `ruby --yjit` to turn it on. It will probably use a lot less memory than TR, and it's probably more likely to deliver the result you're looking for at this time (speed boost, no hassle).

That being said, for some small or specialized applications, TruffleRuby could deliver much higher peak performance. If you don't restart your server often and you have a lot of memory available, then maybe you don't care about warm-up time or memory usage, and TruffleRuby could be the right tool for you. Feel free to run your own benchmarks and also to blog about the results (though if you do, please share as much details about your setup as possible).

[czbond]

@maxime_cb - Great answer, thank you for the detailed response.