My mental model would be, from lowest to highest peformance, something like Ruby/Python < JavaScript < Java/C# < Go < C++/Rust. From what I understand, Java is

My mental model would be, from lowest to highest peformance, something like Ruby/Python < JavaScript < Java/C# < Go < C++/Rust. From what I understand, Java is a huge improvement over Python, Ruby and even JS, but is still not the same as Rust, C++ or even Go. Still, those are rough indicators, and not absolute truth. Yon can usually go really far before being stopped by the absolute strict limit of a language. For example, here's a post about Discord switching from Go to Rust with great success https://discord.com/blog/why-discord-is-switching-from-go-to-rust https://discord.com/blog/why-discord-is-switching-from-go-to..., and here's another about how CockroachDB optimizes Go https://www.cockroachlabs.com/blog/how-to-optimize-garbage-collection-in-go/ https://www.cockroachlabs.com/blog/how-to-optimize-garbage-c.... In the same vein, there's Shopify AOTing Ruby using Sorbet and LLVM https://sorbet.org/blog/2021/07/30/open-sourcing-sorbet-compiler https://sorbet.org/blog/2021/07/30/open-sourcing-sorbet-comp.... All of that to say that I'm not surprised that Rust has better defaults compared to Java, as Rust is supposed to be faster, and option types are a code Rust language feature, while they are a relatively recent addition to Java.